Minnesota's St. Croix River Valley and the Anoka Sandplain: A Guide to Native Habitats

MINNESOTA'S

Of. troix Kiver Valley ^4nokaSandplain

Minnesota Count)' Biological Surrey rfion of Wildlife Division offish and Wildlife Minnesota Department of Natural Resources

University of Minnesota Press Minneapolis I London

Daniel S. Wovcha Barbara C. Delaney Gerda E. Nordquist

Illustrated by Thomas R. Klein and Al Epp

MINNESOTA'S

St. Croix River Valley AND

Anoka Sandplain

A Guide to Native Habitats

Copyright 1995 by the State of Minnesota Department of Natural Resources All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Published by the University of Minnesota Press 111 Third Avenue South, Suite 290, Minneapolis, MN 55401-2520 Equal opportunity to participate in and benefitfrom programs of the Minnesota Department of Natural Resources is available to all individuals regardless of race, color, national origin, sex, age, sexual orientation, or disability. Discrimination inquiries should be sent to MnDNR, 500 Lafayette Road, St. Paul, MN 55155-4031 or the Equal Opportunity Office, Department of the Interior, Washington, DC 20240. This information is available in an alternativeformat upon request. The University of Minnesota Press gratefully acknowledges the generous assistance provided for the publication of this book by the Minnesota County Biological Survey, Section of Wildlife, Minnesota Department of Natural Resources. Printed in the United States of America on acid-free paper. Book and cover design by Diane Gleba Hall Pan opening photo credits: page 2, Minnesota Historical Society photo, used by permission; page 40, MnDNR photo by Carmen Converse; page 166, MnDNR photo by]. C. Almendinger; page 204, MnDNR photo by Carrol Henderson. Library of Congress Cataloging-in-Publication Data Wovcha, Daniel S. Minnesota's St. Croix River Valley and Anoka sandplain : a guide to native habitats / Daniel S. Wovcha, Barbara C. Delaney, Gerda E. Nordquist; illustrated by Thomas R. Klein and Al Epp. p. cm. Includes bibliographical references (p. ) and index. ISBN 0-8166-2483-6 (he). —ISBN 0-8166-2484-4 (pb) 1. Habitat (Ecology)—Minnesota. 2. Habitat (Ecology)—Saint Croix River Region (Wis. and Minn.) 3. Biotic communities—Minnesota. 4. Biotic communities—Saint Croix River Region (Wis. and Minn.) I. Delaney, Barbara C. II. Nordquist, Gerda E. HI. Title. IV. Title: Minnesota's Saint Croix River Valley and Anoka sandplain. V. Title: Anoka sandplain. QH105.M55W68 508.776'6—dc20

1995 94-4091

contents .vn

Preface

St. Croix River Terraces Cottage Grove Dissected Plain

Acknowledgments

ix

Parti A Landscape History of the St. Croix River Valley— Anoka Sandplain Region 3 1. Geologic History and Major Landforms of the Region Bedrock Geology Glacial Geology Major Landforms

4. Influence of European-Americans Logging

JO

Agriculture Urban Growth Summary

38

Part II The Native Habitats and Natural Communities of the St. Croix River ValleyAnoka Sandplain Region

.41

4

St. Croix Moraine Complex Rosemount Outwash Plain Grantsburg Sublobe Till Plain Anoka Sandplain

5. Guide to Part II Key to the Natural Community Fact Sheets

.42

6. Deciduous Forests Oak Forest

.46

Mississippi River Terraces St. Croix River Terraces Cottage Grove Dissected Plain

Formation of the Mississippi and St. Croix River Valleys Geologic Processes since the End of Glaciation 2. Postglacial Landscape Vegetation Influence of American Indians 3. Major Vegetation Patterns at the Time of Euro-American Settlement Vegetation of the Major Landforms

14

.21

Dry Oak Forest

Mesic Oak Forest Maple-Basswood Forest Lowland Hardwood Forest 7. Mixed Coniferous'-Deciduous Forests. White Pine-Hardwood Forest

62

8. Deciduous Woodlands Oak Woodland-Brushland

,67

Mississippi River Terraces Anoka Sandplain Grantsburg Sublobe Till Plain

9. Deciduous Savannas Dry Oak Savanna

St. Croix Moraine Complex

Barrens Oak Savanna

Rosemount Outwash Plain

Sand-Gravel Oak Savanna

72

10. Upland Prairies Mesic Prairie Dry Prairie

SO

Barrens Prairie Bedrock Bluff Prairie

17. Bedrock and Beach Communities Dry Cliff and Moist Cliff Rock Outcrop Lake Beach River Beach

143

18. Aquatic Habitats

757

Summary and Outlook

767

Part III A Guide to Selected Sites in the Region

767

Sand-Gravel Prairie

11. Floodplain Forests 12. Hardwood Swamps Mixed Hardwood Swamp Mixed Hardwood Seepage Swamp Black Ash Swamp

93 98

Appendix 1 13. Conifer Swamps Tamarack Swamp

107

County Checklist of Birds, Mammals, Amphibians, and Reptiles in the Region

205

Appendix 2 Sources of Additional Information

275

Glossary of Technical Terms

277

Bibliography

227

Index

225

Sphagnum Tamarack Swamp Minerotrophic Tamarack Swamp Seepage Tamarack Swamp White Cedar Swamp

14. Shrub Swamps . Alder Swamp Willow Swamp

776

15. Emergent Marshes Mixed Emergent Marsh Cattail Marsh

123

16. Wet Meadows and Fens.. Wet Prairie Wet Meadow Rich Fen Poor Fen

130

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Preface Habitats are places where plants, animals, and other organisms live: for example, prairies, forests, wetlands, caves, cornfields, and city neighborhoods. Each kind of habitat has its own special environment, which is influenced by geologic processes, climate, and the myriad interactions of living organisms with each other and with the rest of their environment. Native habitats are places occupied and characterized by organisms that are native or indigenous to a particular region (as opposed to organisms that evolved elsewhere and arrived in the region relatively recently). The prairies, forests, marshes, and swamps common in Minnesota before EuroAmerican settlement began in the mid-1800s are examples of native habitats; wheat fields, gardens, and city parks are not. This book describes the native habitats that remain in six counties (Anoka, Chisago, Isanti, Ramsey, Sherburne, and Washington) in a diverse region in east-central Minnesota formed by the St. Croix River Valley and the Anoka sandplain. We hope it will be used as a guide and reference by county and city planners, farmers, foresters, architects, park naturalists, developers, landowners, and citizens— that is, by anyone involved with or interested in the natural history of the Region.

In part I we present a brief geologic history of the Region, describe its major landforms and vegetation types, and discuss the forces that have shaped the landscape. The landscape of the Region and its native habitats have changed significantly in the past 150 years, as is evident from a comparison of the maps on the inside front cover and (in more detail) from the county wall maps available as a companion to this book (Minnesota County Biological Survey 1995). The large white spaces on map 2 represent farmland, old fields, logged or grazed forests, suburban neighborhoods, roads, and shopping centers. The few colored areas repre-

sent sites where native habitats have persisted relatively intact to the present. As one sees immediately, very little native habitat remains. Of the 1.5 million acres of land in the Region, less than 90,000 acres, or less than 6% of the total area, remain in native habitat (Marschner 1974, Minnesota County Biological Survey 1995). About 6% of the forests and only 1% of the prairies present at the time of Euro-American settlement remain. Only 3% of the native oak savanna and woodland and about 25% of the forested swamps and shrub swamps are left. Less than 11% of the marshes and wet meadows are still intact. Logging and farming had altered most of the native habitats of the Region by the 1940s. Native habitats remained primarily on inaccessible land or on land of marginal value for logging or agriculture. After 1940, the population of the Region began to grow rapidly (more than doubling between 1950 and 1990), and urban development spread from city centers. The rapid population growth and urbanization brought new patterns of land use to the Region and new threats to the remaining native habitats.

The documentation of the remaining native habitats presented in this book and on the companion wall maps is largely the work of the ecologists, botanists, and zoologists who conducted surveys for the Minnesota County Biological Survey (MCBS) in the six counties of the Region between 1987 and 1990. The MCBS is a systematic countyby-county survey designed to collect and interpret data on the distribution and ecology of native habitats, rare plants, and rare animals. The information gathered by MCBS serves as a foundation for the conservation of critical components of Minnesota's biological diversity. (For more details on MCBS, see Converse et al. 1988 and Converse 1990.) All of the data gathered during the MCBS—including descriptions and locations of natural communities, loca-

M7

tions of rare plants and rare animals, and quantitative samples of native vegetation—are stored in databases in the Natural Heritage Information System maintained by the Minnesota Department of Natural Resources (Minnesota Natural Heritage Program 1992). This book interprets the data collected in the Region before and during the MCBS and highlights major or special natural features. In part II we present information gathered primarily during the MCBS on the composition and structure of the remaining natural communities of the Region. The companion wall maps show in detail the distributions of natural communities, rare plants, and rare animals in each county in the Region. Part III, a guide to selected native habitats, lists by county some of the publicly owned sites in the Region that contain native habitats. For each site, we provide a map, directions to the site, and a brief description of the natural features present. Part III is cross-referenced with

A bedrock bluff prairie overlooking the Mississippi River in southern Washington County in 1891. U.S. Army Corps of Engineers photo by Henry Basse

[viii]

Preface

the descriptions of native habitats in part II to aid the reader in interpreting the natural features at the sites. We hope this book will make the Region's native habitats more visible and more appreciated. These remaining native habitats provide niches for some surprising assemblages of plants and animals. They are also windows into the past, enabling us to imagine what the landscape once looked like and to learn about the processes that shaped it. Because of the great population and development pressures in the Region, these last remnants of the native landscape will persist into the future only under the active guidance of the people whose decisions and lifestyles affect the way land is used. Daniel S. Wovcha Barbara C. Delaney Gerda E. Nordquist

Acknowledgmen ts The authorship of this book is as follows: Daniel Wovcha wrote the landscape history, helped to shape the natural community descriptions, and coordinated the overall production of the book; Barb Delaney wrote the natural community descriptions and the guide section (part III); and Gerda Nordquist wrote and edited the material on animals that appears throughout the book. Thomas R. Klein produced the landscape and community silhouettes, and the site maps in part III, and Al Epp produced most of the other maps. Vera Ming Wong made many of the drawings of rare plants and rare animals. Nan Marie Kane, Don Luce, and Jim Tidwell made additional drawings. All of these drawings have been featured previously in Minnesota's Endangered Flora and Fauna (Coffin and Pfannmuller 1988). We are grateful for the opportunity to use them again here. The material presented in this book is built from the work of many people who have conducted natural history surveys and have chronicled the changes in the landscape of the Region over the last millennium. We recognize their contributions, especially the staff of the Minnesota County Biological Survey (MCBS), who recently surveyed the native habitats, rare plants, and rare animals of the Region. Carmen Converse supervised the survey. John Almendinger, Barb Delaney, Patrick Leacock, David McLaughlin, Kathryn Malody, Thomas Morley, Welby Smith, and Karen Van Norman conducted natural community and botanical surveys. Elmer Birney, Bonita Eliason, Mary Engelhard, Bruce Fall, Carolyn Ferrell, Lynelle Hanson, Lisa Hartman, John Moriarty, Gerda Nordquist, Joe Palmer, Margaret Robertsen, Steve Robertsen, and Steve Stucker did animal survey work. Collections at the University of Minnesota Department of Plant Biology herbarium, James Ford Bell Museum of Natural History, and Department of Entomology provided important historical information on the distributions of rare plants and animals and permanently house the voucher specimens obtained by the MCBS. The Minnesota and Ramsey County historical societies provided the historical photographs used in part I.

Completion of a book of this scope requires the involvement of many people besides the authors in planning, research, data management, writing, clerical work, and review of the manuscript. We wish to acknowledge their contributions. Carmen Converse and John Almendinger directed and shaped the process by which the data from the natural history surveys and other sources of information were incorporated into the present book. Barb Coffin saw the potential interest for a book of this type and, along with Eileen Griggs, guided it through publication at the University of Minnesota Press. Steve Stucker made substantial contributions to the animal text, especially the analysis of breeding bird data collected by MCBS and preparation of material on birds in the book. Carol Dorff, John Haarstad, and Konrad Schmidt also contributed animal information. Roleen Roden helped with manuscript preparation. Mary Miller, Sharron Nelson, and Todd Roden assisted with data compilation and analysis for the MCBS. Karl Bardon, B. J. Farley, Steve Presley, Cindy Thurston, and Jan Wolff contacted land managers and helped with manuscript preparation. Librarians Char Feist, Colleen Mlecoch, and Diane Vejtruba helped gather much of the reference material used in writing part I, and Tony Rodriguez processed hundreds of photographs, enabling selection of those that appear in the book. Carl Conney provided much legal assistance. Ed Gushing helped to shape the writing on glacial and vegetation history and to refine the concept of native habitats we used. Orrin Shane provided organizing ideas and information on the history of American Indians in the Region. Homer Hruby contributed ideas and information on all of the cultural history. J. D. Lehr and Carrie Patterson helped to smooth the presentation of glacial history. Lively discussions over the past several years with Norm Aaseng, Robert Dana, Hannah Dunnevitz, Kurt Rusterholz, and Nancy Sather concerning Minnesota's natural community classification helped clarify the descriptions of native habitats presented in part II. Many people reviewed the manuscript: Tom Anderson, Doug Birk, Nadine Blacklock, Mark [ix]

Cleveland, Dave Crawford, Mark Davis, Tom Dickson, Bob Djupstrom, Don Faber-Langendoen, Joan Galli, John Haarstad, Art Hawkins, Frank Irving, Roger Johnson, Blair Joselyn, Roger Lake, Sue Leaf, Thomas Morley, Dave Olfelt, Gerald B. Ownbey, Lee Pfannmuller, Welby Smith, Harvey Tjader, Scott Zager, and Dave Zumeta. We thank them for the time they spent and for their comments and suggestions. We also wish to thank the people of Minnesota for funding the MCBS and thereby enabling the production of this book. A substantial portion of this funding was approved

M

by the Minnesota Legislature in Chapter 254, Art. 1, Sec. 14, Subd. 9d, as recommended by the Legislative Commission on Minnesota Resources from the Minnesota Environment and Natural Resources Trust Fund. Other State of Minnesota programs that also contributed to the Survey include Reinvest in Minnesota, the Natural Heritage Program, and the Nongame Wildlife Program. The Nature Conservancy contributed funding for the 1987—89 survey of Washington County and has consistently supported documentation of Minnesota's natural features.

Acknowledgmen ts

MINNESOTA'S

J> t. C^roix Kiver I/alley AND Anoka Sandplain

part I A Landscape History of the St. Croix River Valley—Anoka Sandplain Region We tend to take the landscape around us for granted, believing that the land has looked, smelled, and sounded as it does now for as far back in time as we can imagine. But even within the geologically brief period of the past 15,000 or 20,000 years, the landscape of the St. Croix River Valley and Anoka Sandplain Region of eastcentral Minnesota has changed radically: worked and reworked by glaciers, it was covered with vegetation as different as boreal spruce parkland, pine barrens, and prairie as the climate changed and different plant species migrated across the Region. By the beginning of the 1800s, the predominant vegetation in the Region had come to be oak woodlandbrushland, oak forest, and marsh (see map 1, inside front cover). Pine forests, tamarack swamps, and other communities of the northern forest areas of the Great Lakes extended into the northern fringes of the Region. Prairies typical of the expansive grasslands of the midwestern plains extended up the Mississippi and St. Croix river valleys into the southern part of the Region. Maple-basswood forest, an extension of the deciduous forests of the eastern United States, merged with the pine forests in the northern part of the Region and along the St. Croix River Valley. Dakota and Ojibwe lived and hunted in the Region, finding deer in the woodlands, bison on the prairies, and ducks, geese, and wild rice in the marshes. They also traded with EuroAmerican traders who passed through the Region or established posts in the area. In the mid- 1800s, people of European descent began settling in east-central Minnesota, and the landscape changed again. In the course of logging, farming, and building towns and cities, much of the native vegetation was removed and replaced with crops, buildings, lawns, and pavement. Now, just 150 years after the first Euro-American settlers moved into the Region, only small fragments of native habitat remain. Except for these remnants, the landscape now appears unlike anything preceding it. The St. Croix River Valley-Anoka SanJplain Region spans three of North America's major vegetation zones: the conifer-hardwood forest zone, deciduousJorest-woodland zone, and prairie zone. As a result, just before extensive land-clearing began in the mid- 1800s, the type ojvegetation present changed noticeably across the Region. Characteristically northern communities, such as white pine-hardwoodJbrests, tamarack swamps, and poor Jens, were present in the northern part oj the Region. Prairies and oak savannas occurred along riverways in the southern and western parts of the Region. Oak woodland-brushland, oak savanna, and oakforest were especially abundant and stretched across much of the central part of the Region.

[3]

1. Geologic History and Major Landforms of the Region Bedrock Geology Most of the geologic features of the Region, such as plains, hills, river valleys, and lake basins, were produced directly or indirectly by glaciers over the past 20,000 or so years. In some sense, however, the present landscape began forming about 1.1 billion years ago, when the earth's crust parted along a rift stretching from Lake Superior, through Minnesota, to Kansas. In east-central Minnesota, lava flowed up out of the rift and hardened, forming a broad plain of basalt rock across the land (Ojakangas and Matsch 1982).

So much lava poured from the rift in east-central Minnesota that the earth's crust began to sag and fault along it. For millions of years afterward, water carried sediments into the depression formed along the rift by the sagging and faulting. These sediments covered the basalt flows and compacted into layers of sandstone, siltstone, shale, and other sedimentary rocks (fig. 1.1). Still later, beginning about 550 million years ago, eastcentral Minnesota was inundated by a succession of shallow seas, which deposited additional layers of sedimentary rocks over the area. These seas withdrew about 450 million

Fig. 1.1 Sedimentary rocks of the Franconia formation along the Curtain Falls hiking trail at Interstate State Park in Chisago County (see site 10 in part III). The rocks werejbrmed by sediment deposited in a sea that covered the Region during the Cambrian period about 505 million years ago. The smooth upper layer of rock is ajine-grained massive sandstone; the lower dissected layer is sandstone interbedded with siltstone and shale (J. H. Mossier pers. comm. 1993). Contrast the appearance of these rocks with the basalts in the photograph ojthe bedrock outcrop community in chapter 17 (fig. 17.4). The strikingly different nature of the plant communities that later developed on these bedrock types is related to the very different properties of the bedrock.

[4]

Fig. 1.3 Path of the Grantsburg sublobefrom Manitoba and northwestern Minnesota across the Region into western Wisconsin. The Grantsburg sublobe was an ojfshoot of a larger ice lobe, the Des Moines lobe, which traveled southwardfrom Manitoba into Iowa. (Modified from Wright 1972)

Fig. 1.2 Path of the Superior lobe from the Lake Superior basin to its maximum southern position at the St. Croix moraine. The Superior lobe reached its maximum southern position about 20,500years ago, then began melting back to the northeast. (Modifiedfrom Wright 1972)

years ago (Ojakangas and Matsch 1982). The bedrock then underwent millions of years of erosion and weathering, until approximately 2.5 million years ago, when the first of a series of glaciers advanced southward into Minnesota from Canada.

Glacial Geology The glaciers covered the bedrock with ice—perhaps thousands of feet thick in places—and deposited many feet of rock, gravel, sand, and silt. Thus, when the glacial era ended about 10,000 years ago, the underlying bedrock was exposed only along deep valleys cut by glacial rivers. The rest of the land surface was made up of plains, moraines, and river terraces formed by glacial ice lobes and glacial meltwater (see map 3, inside back cover). These glacial landforms dominated the geologic landscape of the Region and greatly influenced the major patterns of vegetation that developed after the ice lobes melted (compare the patterns in maps 1 and 3, for example). The glaciers that most affected the present landscape of the Region came at the end of about 2.5 million years of major glacial activity in the northern United States and Canada. During this period, ice sheets formed over Canada, flowed into the northern United States, melted back, and flowed southward again and again. These glaciers affected all of the land within the state of Minnesota at one time or another. Ice lobes moved earth and rock from one region and deposited it elsewhere, carved out basins, and built ridges. The meltwater from the glaciers scoured river valleys and deposited gravel and sand in broad outwash plains and in lake basins. In spite of the repeated episodes of glaciation over this long period, almost all of the major landscape features in the Region and across Minnesota were created

by the last episode of glaciation. This episode, the late Wisconsin glaciation, lasted from about 35,000 to about 10,000 years ago (Meyer et al. 1990, Wright 1972). The present understanding is that two major glacial ice lobes advanced into the Region during the late Wisconsin glaciation. The first, the Superior lobe, advanced southward from the Lake Superior basin (fig. 1.2); the second, the Grantsburg sublobe, entered the Region from the opposite direction, from the southwest, as an offshoot of a larger ice lobe that originated in present Manitoba and extended to Des Moines, Iowa (fig. 1.3). After the second ice lobe receded and its meltwater drained, the Region contained seven major landforms: the St. Croix moraine complex, Rosemount outwash plain, Grantsburg sublobe till plain, Anoka sandplain, Mississippi River terraces, St. Croix River terraces, and Cottage Grove dissected plain. The distinctive soils, topography, and patterns of lakes, rivers, and wetlands of these landforms greatly influenced the patterns of vegetation that developed later, at least those that were present just before Euro-American settlers began arriving in the mid-1800s. Streams flowing from the melting glaciers also carved the major river valleys of the Region, the Mississippi and the St. Croix. These rivers have attracted humans to the Region for thousands of years; in the mid- 1800s they began to draw Euro-American immigrants, setting the stage for the development of the current landscape. In the following sections we look more closely at the formation of these landforms and river valleys.

Major Landforms St. Croix Moraine Complex The St. Croix moraine complex is a broad band of rolling to rugged hills extending across the Region from St. Paul

Geologic History and Major Landforms of the Region

[5]

northeastward through Washington County and into Wisconsin (see map 3 on the inside back cover). The moraine was formed by the Superior lobe, the first ice sheet to advance into the Region duringO the late Wisconsin glaciO o ation. The Superior lobe scoured rock from the Lake Superior basin; ground it into gravel, sand, and silt; carried it south; and deposited it along the melting margin of the glacier (Wright 1972). The glacier appears to have melted back and readvanced several times before receding for good from the Region about 20,000 years ago. Each time it deposited more sand, gravel, and rock along its edge, forming a broad and rugged moraine (Patterson 1992). The sandy and gravelly till of the moraine is recognizable from its reddish hue, a by-product of the red felsite and sandstone of which the till is formed. This till, when reworked by weather and growing plants, forms coarse, droughty, and relatively infertile soils.

Rosemount Outwash Plain

Associated with the St. Croix moraine complex in southern Ramsey and Washington counties is a broad outwash plain formed of sand and gravel swept outward from the ice by glacial streams as the Superior lobe melted. The outwash plain, like the moraine, has coarse sandy and gravelly soils. However, in contrast to the ruggedness of the moraine, the outwash plain is gently rolling (fig. 1.4) except in a few areas—such as that just east of Woodbury—where the outwash sands were deposited over large blocks of ice, leaving hills and deep depressions now occupied by lakes (Meyer etal. 1990). Grantsburg Sublobe Till Plain

The Grantsburg sublobe till plain is a level to gently rolling plain coveringO the northeast third of the Region. It was -i o formed from material carried into the Region from Manitoba and northwestern Minnesota by the Grantsburg

Fig. 1.4 The nearly level Rosemount outwash plain just northwest of Lake Edith in Washington County. The outwash plain wasformed from sand and gravel deposited by meltwaterfrom the Superior lobe. In thefar background (looking northward toward Bayport) are the fugged hills and ridges of the St. Croix moraine. MnDNR photo by D. Wovcha

Fig. 1.5 The gently rolling Grantsburg sublobe till plain along Highway 24 near Springvale in northeastern Isanti County. Much of the till plain has been logged or converted tofarmland in the past 150years. Patches of native habitat remain primarily in wetland areas. Scattered white pines, such as those in the photograph, have grown up around manyfarms and on cutover land since the logging era of the 1800s.

sublobe, the second major ice lobe to move into the Region during the late Wisconsin glaciation (fig. 1.3). The Grantsburg sublobe covered all of the Region except for parts of Ramsey and Washington counties as it passed eastward into Wisconsin. When it melted, it left behind a broad plain of finely ground gray shale, limestone, and dolostone (fig. 1.5) (Hobbs and Goebel 1982, Meyer et al. 1990, Wright 1972). These deposits are finer than the deposits of the St. Croix moraine. The soils that develop from them are loamy and retain moisture very well (Wright et al. 1973). The soils are also richer in calcium and other minerals than the soils of the St. Croix moraine, the Rosemount outwash plain, and the other sandy and gravelly landforms of the Region. Another important feature of the Grantsburg till plain, in terms of vegetation development, is that it is poorly drained in many areas, with numerous lake and wetland basins. The area of the till plain around Center City in southeastern Chisago County, in particular, is dotted with lakes (see map 4, inside back cover). Anoka Sandplain As the Grantsburg sublobe melted, large sand-laden streams formed from the meltwater. These streams shifted widely

Ice Block Depressions

W

hen the glacial ice lobes were advancing in the Region,large blocks of icesometimesbecame

detached and were buried by glacial till. Other blocks broke off as the ice lobes melted and were buried by sand and gravel carried by glacial meltwater. The buried ice blocks, insulated by a layer of rock, sand, gravel, and sometimes vegetation (including forests), lasted for hundreds or maybe even thousands of years after the main ice sheets had disappeared. When the ice blocks finally melted, the sediment covering them collapsed, leaving expansive holes or depressions. The holes, when filled with water, became lakes, ponds, and wetlands (Gushing 1963, Wright 1972). Most of the present lakes and wetlands in east-central Minnesota are concentrated in areas of end moraine, such as the St. Croix moraine, or in outwash, such as the Anoka sandplain, because these are the areas where ice blocks were most likely to be buried by glacial deposits. Prominent examples of ice block lakes in the Region include Big Marine Lake in northern Washington Count/, the chain of lakes from Round Lake in Anoka County to Lake Josephine and McCarrons Lake in Ramsey County, and the lakes around Cottage Grove and Woodbury in southern Washington County (Meyer et al. 1990, Wright 1956,1972).

Geologic History and Major Landforms of the Region

m

Fig. 1.6 The nearly level Anoka sandplain in west-central Anoka County.

over the newly uncovered ground and deposited sand and gravel in broad, level plains (fig. 1.6) (Cooper 1935, Wright 1972). Later, these streams became dammed, and large, shallow lakes formed across Anoka, Isanti, and Chisago counties (fig. 1.7). The sand carried into the lakes by the streams was spread by currents and deposited across the lake beds, covering the earlier stream deposits in the eastern portion of the sandplain (J. D. Lehrpers. comm. 1993, Meyer 1993, Meyer et al. 1990,1993). These sands generally covered till laid down earlier across the central part of the Region by the Superior lobe and the Grantsburg sublobe. However, scattered across the sandplain are glacial till hills that were high enough that they were not covered by the sand. The sandplain also has numerous lake and wetland depressions that were formed where large blocks of glacier ice were buried by sand and then gradually melted. Mississippi River Terraces

Like the western part of the Anoka sandplain, the Mississippi River terraces are level plains formed from sand deposited by streams that originated from the melting Grantsburg sublobe. At first, these streams shifted over the land along the present Mississippi River Valley, depositing [8]

plains of sand and gravel. However, after the sublobe had melted back from the Region, the largest of these streams formed a well-defined channel between St. Cloud and Minneapolis and became the Mississippi River (Wright 1972). Afterward, glacial meltwater deepened the channel of the

Fig. 1.7 The extent of glacial lakes Anoka, Hugo, and Fridley in the St. Croix River Valley-Anoka Sandplain Region. These lakes were Jormedjrom glacial meltwater as the Grantsburg sublobe wasted between about 16,000 and 13,000years ago. The lakes deposited sands across much of the eastern part of the Anoka sandplain (Meyer 1993, Meyer et al. 1990, 1993, Patterson 1992). (Modifiedfrom Meyer 1993 and Meyer et al. 1990,1993)

Chapter 1

river, and the existing floodplains of the river were left dry, forming river terraces. Above Fort Snelling, the terrace is broad and level; below Fort Snelling, the terraces are renerally more narrow and rise from the river in three distinct levels, with each level representing a former floodplain of the river (fig. 1.8). The streams that deposited the terrace sands were powerful and flowed swiftly, at least compared to the streams that deposited the sands of the adjacent (western) portion of the Anoka sandplain. Therefore, the sands of the Mississippi River terraces are coarser than those of the Anoka sandplain (Wright 1972). In addition, the Mississippi River terraces have fewer lake and wetland basins than the Anoka sandplain. Evidently, most of the glacial ice had melted by the time the terraces formed, and few ice blocks were buried by the river terrace sands. 7

St. Croix River Terraces

As the Superior lobe and the Grantsburg sublobe melted, large glacial lakes formed to the north of the Region. These lakes, including Glacial Lake Duluth and Glacial Lake Grantsburg, drained via rivers down the St. Croix Valley (Meyer et al. 1990, Wright 1990). The first of these rivers cut broad terraces into the sand and gravel deposited along the St. Croix Valley by the Superior lobe. Later, the ancestral St. Croix River eroded the valley more deeply, cutting into the underlying bedrock and forming additional terraces. This left a deep river valley with a series of river terraces and numerous bedrock cliffs and bluffs (fig. 1.9). (See the following description of the formation of river valleys in the Region.) After the valley was deepened, the streams feeding the main river also cut down through the sand, gravel, and

Fig. 1.8 A portion of the Mississippi River terraces just northeast of Lower Grey Cloud Island in southern Washington County. The hillside in the background marks the boundary between the low river terrace in theforeground and a higher terraceJormed when the Glacial River WarrenJlowed through the Mississippi Valley at a higher level. The terraces continue northwestward up the Mississippi River through Ramsey, Hennepin, Anoka, and Sherburne counties. Injact, much of downtown St. Paul is on a river terrace—the St. Paul Cathedral and the capital building sit on a hill that marks the edge of the terrace and the beginning of a higher outwash plain. West of downtown St. Paul, the terraces encompass much of the ground along West Seventh Street below the Summit Hill and Highland Park neighborhoods. Farther upstream, the terraces widen greatly, covering much of southwestern Anoka County and the southwestern third oj Sherburne County.

Geologic History and Major Land/arms of the Region

[9]

underlying bedrock to form deep side ravines along the length of the valley in Washington and Chisago counties (Wright 1972). The ravines along Brown's Creek just north of Stillwater and at Falls Creek in northern Washington County are striking examples of this downcutting. Cottage Grove Dissected Plain

The Cottage Grove dissected plain is the only landform in the Region that was not formed from glacial sediments deposited during the late Wisconsin glaciation (Meyer et al. 1990). While glacier ice and glacier streams were depositing sediments elsewhere in the Region, the Cottage Grove plain was being eroded by water and wind. This erosion left the surface of the plain dissected and strongly rolling (fig. 1.10). The surface of the Cottage Grove plain is covered with a thin layer of windblown silt and till deposited by earlier glaciers. Beneath the thin soils are layers of dolo-

stone, limestone, and sandstone bedrock. These bedrock layers are exposed along many stream valleys and old glacial meltwater drainageways. Because it is an older landform, the Cottage Grove plain also has a well-developed drainage system and generally lacks the lake and wetland basins and poorly drained level areas common to the Region's more recently glaciated terrain. Formation of the Mississippi and St. Croix River Valleys With the exception of scattered buried ice blocks, the last glacial ice in east-central Minnesota—the Grantsburg sublobe—had melted by about 13,000 years ago (Wright 1972). By 12,000 years ago, the main ice sheet that fed the Grantsburg sublobe had melted back into the Red River Valley of northwestern Minnesota and adjacent North

Fig. 1.9 Cliffs along the St. Croix River gorge at Interstate State Park. These cliffs were cut by rivers draining glacial lakes north of the Region between about 13,000 and 10,000 years ago. The rocks of these cliffs are basalts that wereformed about 1.1 billion years ago by lavaflowing from a rift in the earth's surface. The basalts are much more resistant to erosion than the sedimentary rocks that the rivers cut through elsewhere in Chisago and Washingon counties. Therefore, the valley here is steep sided and narrow, in contrast to the wide valley south of the gorge, where the river cut through sedimentary rocks (Ojakangas and Matsch 1982, Wright 1972, Wright et al. 1973).

[10]

Chapter 1

Fig. 1.10 The strongly rolling Cottage Grove dissected plain along County Road 18 west ofAjion in southeastern Washington Country

Dakota and Canada. Glacial meltwater then began to pool in the Red River Valley, forming Glacial Lake Agassiz. The waters of Glacial Lake Agassiz eventually rose enough that they drained over the divide now separating the Red and Minnesota river valleys and flowed down the valley of the present Minnesota River as Glacial River Warren. River Warren was joined by the much smaller ancestral Mississippi River where the Minnesota River now joins the Mississippi River below the bluffs of Fort Snelling. Glacial River Warren was a powerfully erosive river. It cut down through dozens of feet of glacial deposits to the underlying bedrock. Near the present site of downtown St. Paul, a waterfall developed in River Warren where it flowed across an older river channel that had been etched into the bedrock. Over hundreds of years, the bedrock shelf underlying the waterfall eroded upstream beyond the mouth of the Mississippi River. When this waterfall eroded past the Mississippi, the River Warren channel cut below that of the

MnDNR photo by D. Woscha

Mississippi, leaving the Mississippi hanging and forming a second waterfall. The bedrock shelf under this second waterfall eroded upstream over the next 10,000 years to its present location at St. Anthony Falls (Wright 1990). The erosion of the Mississippi River Valley by Glacial River Warren and the migration of these waterfalls produced deep gorges and valleys along the Mississippi River in Washington and Ramsey counties (Meyer et al. 1990, Patterson 1992). River Warren also eroded its channel below the level of the channel of the ancestral St. Croix River, which fed River Warren at present-day Point Douglas in Washington County. This may have sent a similar wave of erosion and valley-cutting up the St. Croix River Valley. However, much of the St. Croix Valley had been deeply eroded previously by drainage from glacial lakes Grantsburg and Duluth to the north (Cooper 1935, Wright 1972,1990). After the oglacial lakes had drained,' the rivers flowing o through the Minnesota, Mississippi, and St. Croix river

Geologic History and Major Landforms of the Region

[11]

Fish of the Region's Rivers

T

he fish found in the rivers of the Rejion today reflect the history of mixing and sortim| of waters during the Pleis-

tocene. Perhaps n0 Singte force has affected the distribution of fish in the state more than fee glaciatiori events of some 13,000 to 20,000 years ago. The advance and retreat of glacial lobes at times converged the riyeis from several drainage systems, white diverting or obstructing the flow of others fUnderhil! 1989). Fish most likely followed trie shifts in water flowage and moved into these glacial lakes; and rivers. As the waters receded and the Mississippi and SJ. Croix rivers took on more of their present appearance,they toff behind them natural barriers, such as the falls at St. Artthony Falls and Taylors Falls,

that blocked or substantially limited, further movement of fish upstream. Three subdrainages of the Mississippi River drainage now make up the rivers and streams of the Region. Although these subdrainages have historical affinities, as shown by the species of fish they share, each also contains different native fisH assemblages, ; The segment of the Mississippi River that flows past Sherburne and Anoka counties and all rivers and streams that drain into this portion of the Mississippi are part of the Upper Mississippi Basin, Within this subdrainage, which originates at Lake Itasca and ends at St. Anthony Falls, 65 native species of fish have been documented (Underbill 1989), Alt but five species—the cisco (Coregonus artedii), lake whttefish (€. c/«peaformis), lake trout (SaMlintisnamaycvsh), finescale dace (Phoxinus neogaem)t and ninespine stickleback (Pungitius

turning southward* By comparison, 118 native fish species, almost twice as many species as in the Upper Mississippi fish community, have been documented from this subdrainage. Nearly all fish species Considered rare in Minnesota occur herer including distinctive specte such as ttie lake sturgeon (Acip&nser fulvme&m), which can exceed 200 pounds, and the paddlefish (Potyodon spathula), which moves its long, spoon-billed snout back and forth as ft forages, The third subdrainage, the St. Croix Basin, originates at the headwaters of the St Croix, Snake, and Kettle rivers and includes the streams and rivers that drain the eastern portions of Chisagp arid Washington counties to where the St. Croix River joins the Mississippi River. Nearly 80% of the 93 species of fish found here are also found in the Lower Mississippi fish community, as well as many of the state's rarest fish. The present distribution of one species, the gilt darter (Pertina evides), is apparently restricted to the upper St. Croix River and its tributaries (Phillips et at 1982); Conversely, 16 other species in the St, Croix ftsh community do not occur above Taylors Falls today. The rapids and cataracts originally present at Taylors Falls did notform an absolute barrier to fish migration, and during high water conditions in the spj^grish were probably able to get past the falls to reach spawning grounds upstream (K. Schmidt pers. comm, 1993). However, the dam constructed at Taylors Falls til the early 1900s prevented many fish, especially the larger species, from passing. Recent accounts describe shovel-

pimgitius)—can be found below the falls as well. The Lower Mississippi Basin begins below St. Anthony Falls

nose sturgeon (ScapMrhynchus piatorynchus) congregated in large numbers below the dam during the spawning season. Poor reproductive success among fish where dams have been constructed is thought to have contributed to the decline of some

and runs past Ramsey and southern Washington counties before

fish species and the disappearance of others from these rivers.

valleys became much smaller. They were unable to carry all

tributary of the Mississippi, the Chippewa River, deposited

of the sediment deposited in them by their tributary streams,

enough sediment in the Mississippi River near Wabasha to

and the river valleys began to fill with sediment. The Mis-

partially dam the river, creating Lake Pepin. Lake Pepin at

sissippi and St. Croix valleys have filled with as much as 100

one time extended upstream as far as St. Paul, but the upper

feet of sediment in places in Ramsey and Washington coun-

end of the lake gradually filled with sediment carried into

ties since the end of the glacial era (Meyer et al. 1990). One

it by the river. As this delta moved downstream past the

[12]

Chapter 1

mouth of the St. Croix River, the sediment dammed the

filling of the Mississippi and St. Croix river valleys with sedi-

St. Croix River, forming Lake St. Croix (Wright 1990).

ment carried by the sluggish postglacial Mississippi and St.

Geologic Processes since the End ofGlaciation

with dead plant material, or peat, and with sediment eroded

Once the river valleys and lakes had formed, about 10,000

on the Anoka sandplain (Wright 1972). The major vegeta-

years ago, the last glacial episode ended. Since then, the

tion patterns that developed after the glaciation were strongly

geologic landscape has changed relatively little. The major

influenced by the Region's geology, closely reflecting the

changes over the past 10,000 years have been the gradual

patterns of the major landforms.

Croix rivers; the gradual filling of lake and wetland basins

Dunes of the Anoka Sandplain unes began to form on the Anoka sandplain about 8,000 years ago during a particularly warm, dry period

D

when vegetation became sparse and strong winds eroded and redeposited the exposed sands. Development of the dunes continued during similar dry periods at about 6,000 and 5,000 years ago {Keen and Shane 1990). Dunes formed mainly

from surrounding uplands; and the formation of sand dunes

are common only far south and east of the Region, on the Atlantic coastal plain. West of the Atlantic coastal plain, they occur only in scattered sandy areas, such as dunes near trie southern tip of Lake Michigan and those on the Anoka sandplain. Because of their drought1/ infertile soils and steep topography, most of the dune areas on the sandplain have never been cultivated. Consequently, they harbor not onty rare and distinctive plant species, but also some of the most significant tracts of native vegetation in the Region, particularly oak savanna and dry prairie. However, in the decades following the droughts of the 1930s, some of the largest of tnese dune areas have been planted with pines, a crop that can persist on the sandy soils and that was believed would control wind erosion on the sandplain. These pines, as they mature, overtop the savanna oaks anrj shade out the native prairie species. Trie pines also produce aciaic needle litter that leaches nutrients from the soils and destroys the organic soil layers that develop under prairie grasses. Other areas of native dune vegetation in the Region have been destroyed recently by suburban development, including construction ot houses and golf courses.

The pines on this dune field in eastern Sherburne County were planted in the 1980s. As they mature, they will gradually shade out the native grasses and forks, until the only evidence of the present oak savanna will be a few scraggly oak trees growing among the pines. in the southern and western part of the sandplain, as shown on the accompanying map. Dune areas are especially extensive within Sand Dunes State Forest in central Sherbume County (see site 23 in part 111). The dune areas contain habitats that aie rare in the rest of the Region, including wind-scoured blowouts and arid dune crests. These habitats harbor species, such as false heather and sea-beach needlegrass, that are adapted to growing on droughty, shifting substrates. Interestingly, some of these species

Another threat to prairies and savannas on dune areas is erosion by ATVs. This dune field is near Elk River in Sherburne County.

Geologic History and Major Landforms of the Region

[13]

2. Postglacial Landscape Vegetation Vegetation began to develop in the Region even before the end of the glaciation. The vegetation then changed dramatically over the next 10,000 or 11,000 years, partly in response to changes in climate and apparently also the activities of American Indians. The first vegetation to develop was patches of spruce trees and perhaps tundra plants around the margins of the glaciers and on buried ice blocks (E. J. Gushingpers. comm. 1992, Wright 1972). By about 11,000 years ago, much of the Region was covered by boreal vegetation dominated by spruce trees, with smaller numbers of paper birch, aspen, black ash, tamarack, balsam fir, and alder (Gushing 1967, Keen and Shane 1990, Webb et al. 1983). Prairie species were also relatively abundant during this period, suggesting that the vegetation was spruce parkland, with many shrub- and grass-covered openings (E. J. Gushing pers. comm. 1992, Eyster-Smith et al. 1991). The land surface probably was highly disturbed by shifting glacial streams and the melting of buried ice blocks, which exposed patches of bare soil (Gushing 1963). Spruce began to decline in east-central Minnesota around 10,500 years ago, when the climate warmed rapidly. The spruce vegetation was replaced about 10,000 years ago by pine barrens and pine forests, as jack pine and later red pine migrated into eastern Minnesota from Michigan and northern Wisconsin (Keen and Shane 1990, Webb et al. 1983). In east-central Minnesota small amounts of elm, black ash, and paper birch were present with the pines. Bracken ferns were abundant in the understory, indicating that the tree canopy was rather open or patchy. Although the climate was warmer and drier at this time than during the glacial period and the period of spruce parkland, it probably was still fairly humid and cool because of the presence of large glaciers north of Minnesota in the Hudson Bay region. About 9,000 years ago, the climate warmed again and

[14]

pine declined in abundance. Prairie herbs began to increase, at least in the western part of the Anoka sandplain, while mesic forests dominated by elm developed near the St. Croix River (Eyster-Smith et al. 1991, Keen and Shane 1990). Oak became more widespread on the landscape as well, most likely forming scrubby thickets in moist areas, such as in deep ravines, along rivers and lakes, and on shaded slopes on the hilly St. Croix moraine (E. J. Gushing pers. comm. 1992). Remnants of pine forest may have been present on some of these moister sites. Small patches of jack pine woodland or savanna likely were present on droughty outwash plains. The climate appears to have continued to warm from about 9,000 to 8,000 years ago. It also became much drier; lake levels on the Anoka sandplain dropped to perhaps as much as 12 feet below their present levels (Keen and Shane 1990). Prairie spread across the landscape during this period. By about 7,000 years ago, prairie had reached its northeastern maximum in Minnesota, about 75 miles northeast of its present position, and covered most of the Region (fig. 2.1) (Webb et al. 1983, Wright 1992). The prairie vegetation of this period did not resemble the tallgrass prairie typical of much of southern and western Minnesota at the time of Euro-American settlement. Rather, it resembled the shorter and more arid midgrass prairies now present in the western Dakotas (Jacobson and Grimm 1986). Prairie—most likely with oak thickets interspersed in draws and on moist, shaded slopes—continued to dominate the Region until about 4,000 years ago, when the climate became cooler and moister (Keen and Shane 1990). In response to the moister climate, the oak thickets began to spread into the prairies. Oak woodland-brushland gradually became the dominant upland vegetation, probably interspersed with marshes and wet prairies. White pine also migrated eastward into the Region at this time as the climate cooled (Jacobson and Grimm 1986). Thus, east-central Minnesota probably contained a mosaic of oak woodlandbrushland and prairie openings, with small patches of oak

Fig. 2.1 The maximum northeastern extent of the prairie-Jbrest border in Minnesota, reached about 7,000years ago. (Modifiedfrom Wright 1992; copyright University of Minnesota Press)

and pine forest on moist sites and extensive marshes in poorly drained low areas. The prairie-forest border moved westward throughout this period of cooling. It reached its present position by about 500 years ago (see the map on page 3) (Webb et al. 1983). Around 300 years ago, the climate became especially moist and cool, and extensive mesic forests of elm, sugar maple, and basswood developed in parts of east-central Minnesota (Grimm 1983,1984). The major vegetation patterns present at the time of Euro-American settlement were then in place.

Influence of American Indians The history of American Indians on the Anoka sandplain and in the southern St. Croix River Valley is complex, and there have been few rigorous archaeological excavations that would help to interpret it. Therefore, ideas on the history of American Indians in the Region are still evolving. However, it does appear that the Region has a long history of use and occupation by American Indians. Campsites unearthed around marshes, lakes, and streams suggest that the Anoka sandplain has been inhabited and hunted on for much of the past 10,000 or 11,000 years. Artifacts found along the St. Croix River Valley indicate that it was a trade route for at least 9,000 years between American Indians living in the northern conifer forest regions and those in the deciduous forests to the south (O. C. Shane pen. comm. 1993). One conclusion that emerges from the tools, bones, and other materials found at sites around the Region is that during the prehistoric period the lifestyles of American Indians were closely tied to the vegetation and animal populations. Three successive American Indian lifestyles or cultural tra-

ditions can be distinguished: the Paleo Indian, the Archaic, and the Woodland. These paralleled the major changes in vegetation and animal populations in the postglacial era. The Paleo Indian tradition coincided roughly with the period when spruce parkland and pine forest dominated the landscape between 9,000 and 11,000 years ago. Evidence for Paleo Indian occupation of the Region comes from spear and javelin points found scattered across the Anoka sandplain (Harrison 1978). The Paleo Indians have traditionally been considered "big-game hunters." They are thought to have migrated into the Region from the Great Plains, following herds of large mammals such as caribou and woodland bison that moved into the area as the ice receded and vegetation began to develop. They lived in small bands and traveled from one temporary campsite to another, their movements determined by the movements of the animals they hunted. Although the Paleo Indians appear to have been adept hunters, wild fruits and nuts were probably as important as animals in their diet (T H. Hruby pers. comm. 1993). It is not clear whether Paleo Indians were ever numerous in the Region—the scattering of artifacts across the sandplain may mean that few lived here. If so, their impact on the landscape may have been small. There is some evidence that Paleo Indians were proficient in killing bison on the sandplain. A site unearthed by peat-digging operations near Coon Creek in Ham Lake Township in Anoka County contained the remains of at least 20 bison that may have been driven into the then swampy land by Paleo Indian hunters (Harrison 1978). In a broader context, it is possible that Paleo Indian hunters contributed to the extinction of giant mastodons and woolly mammoths in North America (Pielou 1991). When the climate became warmer and drier and prairie spread into the Region about 8,000 years ago, a new cultural tradition, the Archaic, developed. The Archaic Indians used the Region more intensively than the Paleo Indians, as evidenced by the abundance of Archaic artifacts and campsites across the Anoka sandplain (Harrison 1978). The Archaic Indians were more sedentary than the Paleo Indians. Many of their campsites on the sandplain contain tools and charcoal, indicating that Archaic Indians set up substantial base camps in certain areas, with smaller seasonal camps for hunting or foraging. Archaeologists have

Postglacial Landscape

[15]

Fig. 2.2 Ojibwe inhabited the St. Croix River Valleyjrom the late 1600s or early 1700s into the late 1800s. Apparent in this 1885 photo of an Ojibwe camp near Taylors Falls are influences on the Ojibwe (such as the cotton dresses) from Euro-American traders and settlers, who began moving into the valley in the 1700s and 1800s.

also found many bison bones dating from this period in the marshes of the Anoka sandplain. From this, they surmise that a large bison herd roamed the prairies of the sandplain and that the Archaic people hunted bison intensively (O. C. Shane pers. comm. 1993). One possible Archaic Indian bison kill site is in southeastern Anoka County, where Rice Creek narrows between two sandy ridges just south of Rice Lake. Eight Archaic projectile points and a partial bison skeleton have been found in the mucky creek bed, suggesting that the site was a popular fording spot for bison, which were ambushed there by Archaic Indians (Harrison 1978). Although the question has not been thoroughly examined for the sandplain as a whole, at least in the vicinity of Horseshoe Lake in Isanti County fire was common during the Archaic period (E. J. Gushing pers. comm. 1993). The Archaic Indians may have burned the prairies in association with bison hunting, as did American Indians living in the Region when European explorers began arriving in the late 1600s. Some time after the climate cooled and prairie gave way to woodland and forest, a new culture developed in the Region, the Woodland tradition. The Woodland Indians were much more numerous than either the Paleo Indians

[16]

or the Archaic Indians, as indicated by a dramatic rise in the number of campsites on the Anoka sandplain beginning about 2,500 years ago (Dobbs et al. 1990). The population increase may have been related to the increased diversity of animals and plants that accompanied the change from a largely prairied landscape to one that was a mosaic of woodland, prairie, and forest. The Woodland Indians set up their camps around the shallow lakes and marshes of the sandplain, taking advantage of the abundant fish, waterfowl, muskrats, turtles, and other small animals in these areas. They also gathered nuts and fruits and hunted deer in the surrounding woodlands. Around 1,200 years ago, a fairly significant change took place among the Woodland Indians of central Minnesota: they became heavily dependent on wild rice. Woodland Indians probably had been harvesting wild rice from the marshes and lakes of the sandplain for some time before 1,200 years ago, but around that time they developed a method for preserving the grain that allowed large quantities to be harvested and stored for later use (Johnson 1985). The intensive use of wild rice was accompanied by larger populations, as evidenced by an increase in the number and size of campsites. House floors have even been found at some Woodland campsites from this period (Wendt 1988).

Chapter 2

Not many years ago. these lakes weie frequented by thousands of wild ducks and geese... Howard Lake and several

Centerville Lakes Area

T

he lakes and marshes around Centerville in southeast-

em Anoka County have attracted humans lor much the time since the glaciers melted h east-central Minnesota. Spear points from Paleo Indians of perhaps 10,000 or 11,000 years ago have been found near Howard Lake. Laler, the area was occupied by Archaic Indians, as suggested dy the numerous Archaic Indian tools—such as drills, scrapers, hammers, and grindstones—found at campsites in the area and associaled with making shelters or clothing and processing food (Harrison 1978). Archaeologists have also found a-tifacts dating from tie later Woodland period on many of the dry sandy ridges in the area. In the late 1600s, when the French explore-s Father Louis Hennepin and Nicholas Perrot traveled through east-central Minnesota, they alluded to Dakota Indians residing in the Centerville lakes area Perrot (1867) observed that the area provided a haven lor the Dakota, as it was "nothing but lakes and marshes, full of wild rice" and was situated off the main travel routes of the Mississippi, Rum, and St. Crow rivers and was therefore relatively inaccessible to the Ojibwe, with whom the Dakota were at war (Harrison 1978]. Some sites in the area, such as a small knoll at the south end of Peltier Lake, appear to have been inhabited Qy American Indians for much of the historic and prehistoric periods. When Euro-American settlers began moving into tie area in the 1840s and 1850s, they found a lancscape with "intensive marshes . .. singularly interspersed with islands of various sizes covered with several kinds of timber" and small areas of dry land "rising abruptly above the level of the marsh and thereby covered with short grass and Sparse Jack Oak trees" or "thickly covered with brush of smsl: growth" (U.S. Surveyor General 1847-1908). Tne grassy upland knolls may well have been American Indian campsites, turned frequently to keep them open and free of brush. The settlers also found the area abounding in wildlife and gave accounts of excellent deer and waterfowl hunting in the 1800s (Dobbs et al. 1990, Goodrich 1905). Historian Albert Goodrich (1905) describes the waterfowl and wild rice present in the area during the early years of settlement:

The Woodland Indians still appear to have moved around quite a bit within the area of the base camps, setting up seasonal camps associated with foraging for nuts and fruits and with deer hunting. The Woodland tradition continued among the American Indians until the arrival of the fur

of the Cer,te:vil!e lakes are very shallow and the rice grows in them to such an extent that in the late summer, the water is entirely obscured and they look like green meadows. The waterfowl feed upon the rice and late in the fall, when the stalks have bent over and fallen beneath the surface of the water, they dive after the rice, refusing to leave this feedini ground until the last open space has frozen across. Residents of the area have recounted stories of canning a hundred pints of duck meat after a day's hunting. In the ISOOs. residents also picked high-bush and tow-bush cranberries around the lakes and netted fish oeneath the ice in the winler when the shal ow lakes *roze to the bottom except near springs and flowing water, where tne fisf. concentrated (Dobbs et al. 1990). The wild rice, waterfowl, deer, and forests around Ins lakes all began to decline soon after Euro-American settlement. The wild rice beds disappeared rapidly around 1900 when tre lakes became muddied, either by agriculture or the introduction of carp (Dobbs et al. 1990). Ducks and geese became less abundant as the wild rice diminished. Deer were hunted intensely f or market and perhaps also for home consumption by settlers and became less common in the late 1800s and early 1900s (Goodrich 1905). A charcoal factory ir Centerville placed such a demand on the surrounding oak forests that oy the 1900s oak trees had been depleted from much of the area and had to be brought in from as far as (he St. Croix River Valley and Wisconsin (Dobbs et al. 1990). Much of the remaining upland vegetation :n the area was cleared for cropland by the ea-ly decades of the 20th century, and drainage dutches were constructed throjgn the marshes. At present, game animals such as ducks, geese, ard whitetailed dee' are again common in the area, but little native vegetation remains. A few isolated matches of oak forest are all thai is left of the native upland vegetation. Some fairly large marshes ard swamps remain around the lakes, aut they generally lack many of the native plant species characteristic of wetlands in areas undisturbed by agriculture or drainage dilches. Instead, the present marshes and swamos contain almost exclusively common species such as cattails and speckled alders or have been invaced by aggressive weedy species such as reed canary-grass.

trade and Euro-American settlement in the Region in the 1700s and 1800s. At about the same time as the late Woodland tradition based on wild rice processing developed in east-central Minnesota, another cultural tradition, the Oneota, appeared

Postglacial Landscape

[17]

in southern Minnesota. The Oneota tradition was based on corn and bean agriculture and developed in southeastern Minnesota as farming and other ideas spread north from centers in Missouri and Illinois. The Oneota established large villages along major riverways. Although the Oneota generally lived south of the Region, there was an Oneota fishing camp on the St. Croix River near Marine on St. Croix (Gibbon 1973), and the agricultural practices of the Oneota appear to have spread among the Woodland Indians of the Region; the late Woodland Indians grew small plots of corn, beans, and squash on river floodplains or on mudflats adjacent to lakes (Harrison 1978). Another important aspect of American Indian activity in the Region during the postglacial era was the use of the St. Croix River as a trade route between tribes livingO in the northern forests and tribes living south of the Region. Artifacts found in caves along the river indicate that American Indians traveled through or inhabited the valley for at least 9,000 years before the arrival of Euro-American settlers (O. C. Shane pers. comm. 1993). Some of the more conspicuous trade goods found along the river are copper from the Lake Superior basin and adjacent areas and red pipestone from northern Wisconsin (Dobbs et al. 1990). These goods were evidently transported down the St. Croix to the central and lower Mississippi Valley. American Indians traveling along the river probably also brought medicinal and food plants from one area to another, thereby introducing new plants to the river valley. The heavy use of the river as a travel route may have caused other changes in the lands along the river, such as increased frequency of fire on the wooded and prairie-covered river bluffs. It is also likely that American Indians regularly inhabited many sites along the river during the prehistoric era. The first written account of American Indian life in the Region comes from Father Louis Hennepin, who was captured by a group of Eastern Dakota near St. Anthony Falls in 1679 and taken up the Rum River to spend a winter at their camp near Lake Mille Lacs (Hennepin 1938 [1683]). Hennepin recorded that the Dakota relied heavily on wild rice and fish—thus most archaeologists would consider the Dakota part of the late Woodland cultural tradition. Hennepin's account and the 1680s memoirs of another Frenchman, explorer Nicholas Perrot, imply that Eastern Dakota also lived at the time in the lake-dotted area around present-

[18]

day Centerville in southeastern Anoka County, where they found abundant wild rice, waterfowl, fish, deer, and other animals (Harrison 1978, Perrot 1867). At this time, however, the Eastern Dakota were moving southward out of the Region toward the riverine environment of southeastern Minnesota and the prairie areas of southern and southwestern Minnesota. In part, they were drawn to hunt bison on the prairies southwest of the Mississippi River and to gain access to traders moving into southern Minnesota. In part, they were driven by Ojibwe moving southward from the Lake Superior region (fig. 2.2) (Holzkamm 1983, Little 1985). They may also have moved south following climatic cooling and changes in the vegetation in the prairie-forest border area. At any rate, by the mid- 1700s, the Dakota had abandoned the Lake Mille Lacs area, possibly moving to wetland areas along Rice Creek in western Anoka County (Goodrich 1905). By the 1780s, the Mille Lacs Dakota and the Dakota near present-day Centerville had been pushed to land south and west of the Mississippi River. Afterward, until the removal of the Ojibwe and Dakota in the mid- 1800s, much of the Region formed a buffer between the two tribes and was used mainly for hunting. The Anoka sandplain is thought to have been especially contested because of the abundance of deer in its woodlands (Goodrich 1905, Hickerson 1965,1970). Participation in the fur trade in the 1700s brought changes in the lifestyles of the American Indians in the western Great Lakes area. In general, the fur trade encouraged American Indians across much of the area to hunt and trap animals such as bison and beaver much more intensely than before, contributing to their extirpation over wide areas. The fur trade may also have increased hunting pressure on large animals such as bison, elk, and deer by disrupting other food-gathering activities such as fishing and wild ricing (Hickerson 1965). The periodic warfare between the Dakota and Ojibwe within the Region may have interfered with the fur trade, causing the Region to be less heavily trapped and hunted than other parts of the western Great Lakes area (Hickerson 1965, Little 1985). Even so, the fur trade probably contributed to the extirpation of bison and elk, which had largely disappeared from the Region by the 1830s, well before extensive Euro-American settlement. The effect of the fur trade on other animals in the Region, such as beaver and muskrat, which were trapped for their skins, and deer,

Chapter 2

which were hunted for their hides and to supply traders with meat, is not well documented. One well-documented way in which American Indians altered the landscape of the Region during the historic era was by setting fire to the vegetation. Numerous accounts from Euro-American explorers and settlers tell of American Indians burning the prairies, savannas, and woodlands

Bison and Elk along the Mississippi River

H

erds of bison and elk grazec the prairies along the Mississippi River before Euro-American settlement. Bison were less abundant ir- the prairies along the Mississippi River thar in the more extensive tallgrass prairies in southern and western Minnesota (Hickerson 1965). However, Father Louis Hennepin reported in 1680 that bison were abundant in the vicinity of the river for many miles above and below St. Anthony Fails (Hennepin 1938 [1683]). Bison were also numer-

of the Upper Midwest during the early 1800s (Goodrich 1905, Grimm 1984, Harvey 1980). The explorers and settlers recognized that the fires had a significant impact on the vegetation of the Midwest. For example, Joseph Nicollet, who explored the Mississippi River above Fort Snelling and later the territory between the upper Mississippi River and the Missouri River, wrote in 1838 (Bray and Bray 1976):

ous enough on the river terrace prairies to catch the attention of Eastern Dakota living in the Lake Mille Lacs area, who journeyed to these prairies and others west of Lake Mille Lacs to hunt bison (Johnson 1985;. Henry Sctioolcraft, who traveled the upper Mississippi from the headwaters lakes to Fort Snelling in 1820. stated that the Eastern Dakota sometimes killed "immense numbers" of bison on the prairies along the upper Mississippi (Schooled 1953 [1821]). Members of Schoolcraft's party spent a day themselves tnat same year hunting bison along the river while descending from Little Falls to just above St. Cloud. Al that time, bison were probably already scarce across much of Minnesota as a result of being hunted commercially for their tongues and hides during the later part of the fur trade era. By the 1830s. bison had sisappea-edfrom the prairies along the Mississippi River above SI. Anthony Falls (Schoolcraft 183d). When a few bison were killed near St. Cloud in 1855 and 1866, the St. Cloud Democrat las reported in Swanson 1940) was prompted to report that it was "the first time in a number of years, that these shaggy monsters have been so near to us. They are row moving about m large herds." Like tne bison, elk were most abundant in Minnesota in the prairie regions; however, they also inhabited woodland areas during the winter (Fashmgbauer 1965). Elk River and Elk Lake in Sherburne County were named for the herds of elk that inhabited the area, as confirmed by the observations of Zebulon Pike in the early 1800s and later explorers and fur traders (Pike 1895, Upharn 1969). Elk declined rapidly in Minnesota m the 1800s, largely because of excessive hunting. Schoolcraft observed elk on the Mississippi River prairies in 1832, but they became rare in eastcentral Minnesota soon after, Several elk were seer along the Sunrise River in Chisago County as late as 1854, but by the late 1800s, the only elk in Minnesota we<e in the extreme northwest (Fashingcauer 1965). During tne 1930s, when severe droughl caused the levels o( many lakes in Minnesota to drop by several feet, elk antlers were retrieved from shallow lakes across southern and central Minnesota, confirming earlier accounts that elk roamed over all of the prairie parts ol the state and into the edges ol the forests [Breckenridge 1949).

Postglacial Landscape

[19]

All the prairies watered by the Mississippi and the Missouri are the work of the Indians who destroy by fire the rich vegetation to assure themselves animal food. Let the vast and shorn prairies . . . remain untouched and the forests, with time, will appear.

American Indians started fires for many reasons besides assuring themselves food. According to William Keating (1824), a geologist who traveled up the Mississippi to Fort Snellingin 1823: The Indian frequently sets the prairies on fire in order to distract the pursuit of his enemies by the smoke, or to destroy all trace of his passage; to keep the country open, and thus to invite the buffalo to it; to be able to see and chace [sic] his game with more facility; as a means of communicating intelligence at a distance with a view to give notice to his friends of his approach, or to warn them of the presence of an enemy. The [European fur] traders often burn the prairies with the same view. Independent of these, the fires of [Indian] encampments frequently spread in dry weather, and burn away the grass to a great distance.

American Indians also used fire to ease travel through dense vegetation; to flush, concentrate, confuse, or injure large animals they were hunting; and to kill and dry trees for firewood. Early accounts most commonly mentioned American Indians using fire as an aid in hunting or to alter the vegetation to attract animals such as deer and bison. The American Indians that lived along the upper Mississippi were especially dependent on fire for hunting bison, as they did not have horses (Schoolcraft 1953 [1821]). Therefore, the prairies adjacent to the Mississippi River—such as those in Sherburne and Washington counties—probably burned regularly, perhaps even annually. Fires would have occurred on the landscape even without being set, but the intentional (as well as accidental) setting of fires in the Region by American Indians greatly increased their frequency (Grimm 1984,1985). The displacement of the Dakota from the Region by the Ojibwe may have reduced fire frequency, as the Ojibwe were traditionally forest-dwelling and used fire less extensively than the Dakota, who had a long tradition of burning prairie and woodland vegetation (Johnson 1985). The development of maple-basswood forests in the area beginning about 300

[20]

years ago is evidence of a reduction in fire incidence in east-central Minnesota that coincided roughly with the movements of the two tribes southward. However, the development of maple-basswood forests also coincided with a general cooling trend that began about 300 years ago (Grimm 1985). In summary, the most widespread impact of humans on the landscape of the Region before the time of EuroAmerican settlement probably came from the burning of prairie and woodland vegetation by American Indians (Curtis 1959). American Indians may have depleted animal populations locally at times through hunting, but evidence indicates that until the fur trade era American Indians harvested animals in ways that did not seriously deplete populations over large areas (Smith 1975, Spector 1985, Watrall 1985). The introduction of the fur trade intensified certain hunting practices, as reflected in the rapid decline of animals such as beaver, bison, and elk across North America in the 1700s and 1800s, even while American Indian populations were vastly reduced by introduced diseases such as smallpox, influenza, and the common cold. Plant populations may also have been depleted locally at times, although at least during food gathering, American Indians harvested primarily the seeds, fruits, or other renewable parts of plants (Curtis 1959). American Indians did transport plants from one area to another, including cultivated plants like corn and beans as well as wild species like butternut and wild leek that were prized for their grains, nuts, fruits, or bark. Agriculture, which required the clearing of vegetation, probably was conducted on a small scale in the Region. It likely was restricted to areas such as river floodplains where much of the vegetation could be cleared by girdling trees and where the soils were soft enough to be worked with wood and bone digging sticks and hoes. Excavations at American Indian campsites and village sites in the Upper Midwest indicate that the vegetation around the camps was often disturbed enough to encourage the growth of weedy species such as poison ivy and ragweed (Dorney 1981, Johnson 1985). Another possible impact was cutting of fuelwood, which may have depleted forests surrounding larger and more permanent campsites or villages.

Chapter 2

3. Major Vegetation Patterns at the Time of Euro-American Settlement At the time of Euro-American settlement, the landscape of the Region was dominated by scrubby oak woodlandbrushland, or oak barrens or openings, as woodland was often called by early settlers and land surveyors in the Region. Marshes and swamps were extensive in parts of the Region, and there were also patches of prairie and forests (see map 1, inside front cover). We know this about the vegetation in part from descriptions in the journals of explorers and early Euro-American settlers but mainly from data on trees and other features of the vegetation collected in the Region between 1847 and 1857 by surveyors working for the General Land Office of the U.S. government (U.S. Surveyor General 1847—1908). Statistical analyses and comparisons of General Land Office survey records with information from soil maps, geologic maps, and recent climate data suggest that the major patterns of vegetation within the Region just before extensive settlement were most strongly influenced by climate, fire, and hydrology (Baker and Kuehnast 1978, Baker et al. 1985, Hobbs and Goebel 1982, Meyer et al. 1993, University of Minnesota 1975, 1980, U.S. Geological Survey undated). Climate, of course, had a strong general influence on the vegetation. The cold winters and dry summers explain why the land surveyors recorded oak trees and prairie grasses in their notes rather than cacti or palm trees. Climate also partly accounted for noticeable patterns of change in the vegetation from north to south and east to west within the Region. In the cooler, moister northeastern part of the Region, the surveyors found white pine-hardwood forests, poor fens (or "cranberry marshes"), and other characteristically northern plant communities. Many of the plants that composed these communities reached their southern limit in Minnesota here, partly in response to changes in temperature, rainfall, evaporation, or some other aspect of climate (Curtis 1959). In contrast, in the southern and western parts of the Region, the surveyors recorded prairies and savannas. These occurrences marked the eastern boundary

of the prairies and savannas that extended across southern and western Minnesota. In all likelihood, however, prairie and savanna would not have been present in the Region in the mid- 1800s were it not for fire. The fires that burned large areas of the Region maintained the prairies and savannas and prevented the development of mature forests across most of the southern and central parts of the Region. These fires interacted with geologic features of the landscape, including soils, topography, lakes, and streams, to produce striking patterns in the overall vegetation of the Region. The relationship between fire, landform, and the major patterns of the upland vegetation becomes apparent when one compares maps 1 and 3 (inside front and back covers). In general, forests occurred in areas (such as the Grantsburg sublobe till plain) that have loamy, moistureretaining soils or strong firebreaks, such as extensive wetlands or rugged hills, and prairies were present on landforms (such as the Mississippi River terraces or Cottage Grove dissected plain) that have coarse, droughty soils or few lakes or wetlands. Oak woodland-brushland dominated areas with relatively droughty soils but also many firebreaks, including much of the Anoka sandplain and the St. Croix moraine. Aspen woodland-brushland dominated areas with loamy or clayey soils that burned frequently, primarily because they were downwind from droughty, fire-prone areas. The fact that most fires in the Region were probably started by American Indians (Dorney 1981, Grimm 1985) also affected the overall pattern caused by fires. Instead of occurring randomly across the landscape, fires probably were concentrated on hunting grounds, near campsites or villages, and along travel routes. The third major influence on vegetation patterns was hydrology. Much of the central part of the Region is covered with shallow basins and poorly drained land along sluggish streams. Swamps, marshes, wet meadows, and fens developed in these wetland areas and covered a fifth of the

[21]

Mississippi River Terraces

landscape at the time of settlement (Marschner 1974). Wetlands were especially numerous on the Anoka sandplain and Grantsburg sublobe till plains, the Region's most level and poorly drained landforms. Like the upland vegetation, the wetland vegetation was influenced by climate: northern plant communities such as tamarack swamps and poor fens were present in the northern part of the Region, and prairies and wet meadows were more common in the south. The wetland vegetation was also influenced by fire, which sometimes swept off uplands during drought years and burned through wetlands, maintaining open, treeless communities such as wet prairies and wet meadows. Hydrology was also a major influence on the vegetation along the Region's larger rivers and streams.

Extensive floodplain forests developed along the St. Croix and parts of the Mississippi and other rivers in response to the particular conditions created by annual river flooding and drawdown.

Vegetation of the Major Landforms Because the vegetation of the Region varied so distinctly by landform at the time of Euro-American settlement in the mid-1800s, the following sections examine in more detail the major vegetation patterns on each of the seven major landforms. Information on local patterns—that is, patterns caused by such things as variation in soil chemistry, plant dispersal, or the presence of groundwater seepage—is pre-

Fig. 3.2

The bearing trees of

Sherburne County as recorded by the General Land Office surveyors between 1850 and 1855. Each small square represents a tree. Notice the striking absence of trees to the south and west of the Elk River (arrow). Fires (probably started by American Indians) burned the land along the Mississippi and spread northward, fanned by prevailing southwest winds, until they were blocked by the Elk River. Prairie occurred south and west of the river, wherejires were common, and woodlands occurred north of the river. The lakes and wetlands southwest of the Elk River also inhibited the spread offire, as shown by the trees scattered around their margins.

[22]

Chapter 3

Anoka Sandplain

Fig. 3.1 ^resettlement pattern of^vegetation across the Mississippi River terraces and the Anoka sandplain. The vegetation is shown along a hypothetical transect (AA'J such as one might encounter in travelingJrom Orrock southwest through Becker to the Mississippi River in central Sherburne County. In this area, the Mississippi River terraces were dominated by prairie and oak savanna, while the Anoka sandplain contained oak woodland on the uplands and wet meadows, marshes, and swamps in the lowlands. The sandplain also had savanna and prairie on sand dune areas, as shown. The elevation along the transect risesfrom about 900feet at the Mississippi River to about l,000jeet on the Anoka sandplain.

sented in some of the descriptions in part II of the present natural communities of the Region.

the Elk River, the township contained brushy thickets of northern pin oaks, bur oaks, and shrubs (fig. 3.2).

Mississippi River Terraces

Anoka Sandplain

At the time of Euro-American settlement, prairie dominated much of the Mississippi River terraces in Sherburne, Anoka, and Washington counties (fig. 3.1; also, compare maps 1 and 3). Explorer Henry Schoolcraft (1953 [1821]) described the prairies along the Mississippi River in southeastern Sherburne and western Anoka counties as "of the richest kind," with a black, marly soil composed largely of organic material. Schoolcraft's description indicates that the prairies may have been mesic or tallgrass prairies, which are extremely rare in the Region at present. Schoolcraft observed that American Indians commonly burned the prairies along the river to corner bison. The fires, once started, spread readily on the level, sandy terrain, maintaining the open prairies. Schoolcraft also described scattered clumps of "dwarf black oak" trees on the prairies. These were probably either bur oaks or northern pin oaks rather than black oaks, and they formed patches of oak savanna or "oak openings," as the early land surveyors often called them. For example, the surveyor of Big Lake Township in Sherburne County reported that the "portion [of the township] lying south of the Elk River is Burr Oak openings and prairie." North of

Oak woodland-brushland dominated the uplands of the Anoka sandplain, while the lowlands contained numerous and sometimes extensive marshes, wet meadows, and tamarack swamps (fig. 3.1). The description of Santiago Township in Sherburne County by surveyor Oscar Davis in 1855 is typical: This township is generally level and in the south part are numerous marshes. The north part is slightly rolling with scattering groves of timber and dense thickets of brush. The timber in the south part is small scattering Black [northern pin] and Burr Oak, Aspen and some Tamarack swamps. . . . The north part is timbered with scattering White, Black and Burr Oak, Lind [basswood] and Elm.

The brush he mentioned was probably made up of young northern pin oaks that had resprouted from tree stumps after fires, along with hazelnut bushes, prickly ash and, in moist places, young aspens. Why the dominant upland vegetation changed from prairie and savanna on the Mississippi River terraces to woodland-brushland on the adjacent Anoka sandplain is not entirely clear. It seems likely, however, that the change was related to a difference in the frequency of fire on the

Major Vegetation Patterns at the Time of Euro-American Settlement

[23]

General Land Office Surveys

S

urveys directed by the General Land Office of the U.S. Congress were condacted in the St. Croix River ValleyAnoka Sandpiain Region between 1847 and 1857 (U.S. Surveyor General 1847-1908). Their main purpose was to subdivide and catalog tne land so it could be sold to tarmers, loggers, railroad Ouilders, and others (Bourdo 1956, Bryan 1978). At the beginning of a survey the iand was divided into townships, each 6 miles square. The townsnips were then divided into 36 1-mile-square sections. The surveyors were to establish tne township and section lines by compass and measuring chain and to place marker posts at the corners of all sections and at tie ha.(way point of each section line. They then located the section-corner posts in relation to the nearest suitable trees. Tnese trees were termed bearing or witness trees. At each section corner t-ne surveyors selected fcur bearing trees, one in each of the lour sections meeting at that corne;. At quartersection corners the surveyors selected two bearing trees, one in each of wo diagonally opposite quarter sections. They recorded the diameters of the bearing trees, their direction and distance from :ns corner post, and the tree soecies. By plotting on maps the species, diameters, snd distances of the bearing trees as recorded by the surveyors, we can now obtain a picture of the structure and species composition of the vegetation in the Region at the time of Euro-American settlement (see illustration) [Bourdo 1956. Bryan 1978. Grirnm 1984).

As the surveyors walked the section lines, they afso recorded the general character of the vegetation, such as "oak thicket" or "scattering timber" or "prairie"; the presence of swamps, streams, and lakes; and tne distances along the line at which tiese features occurred. We can now use this information to create maps of the vegetation types present at that time, including prairies, oak wests, and marshes. (Francis Marschner's nap of the original vegetation of Minnesota [see map 1, inside front cover] was probably composed at least in part from these section line rotes.) Finally, the surveyors wrote descriptions of the overall nature of t^e township, paying particular attention to the presence or absence of timber suitable for logging arri waterfalls suitable for power. They also noted whether the soils were good for farming. The surveying was difficult work, and the surveyors worked under contract with the General Land Office, so at times some were no doubt tempted to take shortcuts and fabricate surveys of lands they did not actually visit. Overall, however, the survey results give the nest detailed picture we have of the landscape as it appeared before extensive clearing and settlement of iand in the Region. When interpreted in combination with modern data on tne nteraction of vegetation with climate, soils, topcgraphy, and hydrology, the General Land Office survey data y>eld reasonably accurate reconstructions of the vegetation (Bourdo 1956, Bryan 1978, Grimm 1984).

Locations and species of the bearing trees recorded by a General Land Office surveyor in 1847 in a township in the Centerviile lakes area of southeastern Anoka County. The relative sizes of the letter codes on the plot indicate the relative diameter of the trees. Notice that the trees east and north of the lakes are often large and are species that are sensitive to fire, such as sugar maple, elm, and ash. The trees west of the lakes are smaller and are generally species that are adapted to frequent fire, such as oaks and aspen. This pattern probably was caused by fires that swept across the sandplain from southwest to northeast.

LEGEND Letrer s ze indicates re a:ive tree diairs^r. Shaded areas indicate water :odies. AH AS Bt BK BC BL

Ash Aspen Birch Black Oak Bur Q=k Bjtterut

HI Hickory IR iroflwood JO Jack Oak (Northern PTL Oa-i or Red Oax}

LI

Linden (Basswcadi MA Waste SU Sugar Maple TA Ta-narack WO White Oak

EL Elm

[24]

Chapter 3

Fig. 3.3 Construction of the Twin City and Lake Superior Railway across the Anoka sandplain in Chisago County around 1907. Note the oak savanna with evenly spaced trees. Frequent low-intensity around fires favored the growth of prairie grasses andforbs beneath the trees.

two landforms: either fewer fires were started on the sandplain, or the numerous lakes, wetlands, and streams of the sandplain prevented fires from spreading very far. Grazing by herds of bison and elk on the Mississippi River terraces, a difference in soil fertility on the two landforms, or coarser soils and a lower water table on the river terraces are other possible reasons for the difference. Small patches of prairie, oak savanna, and oak forest were scattered within the woodlands of the Anoka sandplain (fig. 3.3). The prairies and savannas were generally on droughty sand dune areas. The forests were generally on isolated patches of more fertile glacial till or on places protected from fire, including uplands surrounded by wetlands and areas north and east of lakes, marshes, and swamps. Interestingly, many of the American Indian campsites on the Anoka sandplain were on peninsulas or on the north and east sides of lakes and marshes (O. C. Shane pers. comm. 1993). The siting of camps in the "fire shadow" testifies to the prevalence of fire on the sandplain. The northern and eastern parts of the sandplain also had scattered white pine and white pine-hardwood forests, especially around the lakes and wetlands between Hoffman Lake in Isanti County and North Branch in Chisago County.

Portions of the sandplain were covered almost entirely with marshes and swamps. Columbus Township in Anoka County (the site of much of the present Carlos Avery Wildlife Management Area) was described as "nearly all marshes and tamarack swamps," and the area around Elaine in Anoka County was called "one dense marsh, interspersed at intervals with numerous islands, small lakes or ponds and tamarack swamps." There were also many wet meadows, wet prairies, and poor fens in the shallow basins and wet depressions of the sandplain and on lowlands along streams such as the Rum River. The wet meadows and wet prairies were prized for hay by early Euro-American settlers and were often noted specifically by the surveyors. "Sunrise Meadow" along Goose Creek just east of Harris in Chisago County was reported as having "the best wild hay of any meadow in this section of the country." The surveyor of Columbus Township also reported many floating marshes, which were probably rich fens around the margins of shallow lakes and ponds. Grantsburg Sublobe Till Plain

The Grantsburg sublobe till plain was heavily wooded with oak, aspen, basswood, elm, sugar maple, and white pine

Major Vegetation Patterns at the Time of Euro-American Settlement

[25]

Grantsburg Sublobe Till Plain

Fig. 3.4 ^resettlement pattern of vegetation across the Grantsburg sublobe till plain and the adjacent St. Croix River terraces. The vegetation is depicted along a hypothetical transect (AA'/) through southern Chisago County, Jrom Chisago City east to the St. Croix River. The till plain and river terraces in this area were heavily wooded with deciduousJorests on the uplands andjbrested swamps in the lowlands. Floodplain Jorests occurred in a band along the St. Croix River. The elevation changes along the transectJrom about 950feet on the Grantsburg sublobe till plain to 700Jeet at the St. Croix River (see map 4, inside back cover).

(fig. 3.4). Oak and aspen were present mostly along the border of the till plain with the Anoka sandplain and St. Croix moraine (compare maps 1 and 3). Here, fires from the adjacent oak woodlands of the Anoka sandplain and St. Croix moraine occasionally burned into the edges of the till plain. The result was either a thick growth of young aspens and shrubs, or oak woodland-brushland, or forests composed of northern pin oak, bur oak, white oak, and aspen. Fires probably did not spread very far into the till plain; they were halted by a combination of numerous lakes and wetlands and lush vegetation on the moist, fine-textured, fertile soils. Therefore, in the interior of the till plain, firesensitive trees such as basswood, elm, sugar maple, and butternut increased in abundance, and the aspen woodlands and oak forests graded into maple-basswood forests. For example, in Isanti Township in Isanti County, which borders the Anoka sandplain, the forests were composed of northern pin oak, white oak, aspen, and prickly ash, while Nessel Township in Chisago County, which is more isolated from the sandplain, had mesic forests of large sugar maples and basswoods. In general, maple-basswood forests were most common on the Grantsburg sublobe till plain in the southeast quarter of Chisago County, where the lakes near Chisago City would have blocked fires from the Anoka sandplain and the St. Croix moraine to the south and west, and in northern Chisago and Isanti counties, where wetlands would have stopped fires spreading northward from the sandplain.

[26]

In addition to maple-basswood and oak forests, the Grantsburg till plain had several characteristically northern communities. Tamarack swamps and poor fens developed in lowlands. White pine or white pine-hardwood forests were present on uplands, primarily in the vicinity of Little Stanchfield Lake in northern Isanti County and east of Goose Lake in northern Chisago County (Trygg 1964). St. Croix Moraine Complex

Most of the St. Croix moraine complex was covered by oak woodland-brushland (fig. 3.5) of scattered northern pin oak, bur oak, white oak, and aspen trees, with underbrush of young oak and aspen sprouts, hazelnut, and prickly ash. The southeast part of Hugo Township on the moraine in Washington County, for example, was described by one of the land surveyors as "high rolling land with a soil of light loose sand and stony, covered with short grub Jack [northern pin] and Burr Oak trees and small brush." Like the Anoka sandplain, the St. Croix moraine probably burned frequently, in part because of its coarse sandy and gravelly soils. The fires maintained the oak woodlandbrushland that dominated the moraine. The rugged hills of the moraine probably prevented the fires from spreading evenly, however. Shaded north- and east-facing slopes and deep ravines remained moist enough to resist burning and contained pockets of oak forest dominated by white oak, northern pin oak, and bur oak. Patches of oak forest also were present on the moraine to the north and east of lakes and wetlands. In May Township in Washington County, the

Chapter 3

St. Croix River Terraces

Floodplain

land surveyor found "one grove of good oak timber on the east side of Cornelian Lake," with the remainder of the township covered by "oak barrens." Small patches of prairie were present on some parts of the moraine. Rosemount Outwash Plain

The Rosemount outwash plain was mostly covered by prairie (fig. 3.5). In some places the land surveyors described the prairie as "good," indicating that it may have been mesic prairie. The Rosemount outwash plain also had large areas of bur oak savanna, in which bur oak trees were scattered among prairie grasses. For example, almost all of Baytown and West Lakeland townships on the outwash plain in central Washington County was described as "beautiful Burr Oak openings." Some areas of savanna had a combination of northern pin, white, and bur oak trees. Brushy oak woodland may also have covered parts of the outwash plain. St. Croix River Terraces

The vegetation of the St. Croix River terraces varied dramatically from south to north in the Region. South of Stillwater along Lake St. Croix, where the river terraces often rise abruptly from the water, they were dominated by prairie, as indicated in this description by Reverend R. T Boutwell, a member of Henry Schoolcraft's 1832 expedition up the river (Mason 1958): The shores of this lake are the most picturesque of any lake of the size I have witnessed. A dozen or 20 mounds rising in sugar loaf or pyramid form, may be seen at one glance,

covered with the most beautiful carpet of green, with hardly a shrub.

The high, rocky bluffs along the lake had bedrock bluff prairies with red cedars scattered in crevices in the rocks (Schoolcraft 1834). The low, sandy terraces along the lake— such as those near Lakeland and Bayport—had what the land surveyors described as "prairie bottom (wet)" or "poor prairie bottom," sometimes with thinly scattered bur and northern pin oak trees. These places likely were wet prairie and, where trees were present, oak savanna. Farther from the river, on the higher terraces, the surveyors reported "first rate prairie" or "second rate prairie," which was probably mesic prairie. The river terraces also had scattered patches of oak forest and oak woodland of bur, northern pin, and white oaks, generally in ravines or on steep slopes between the upper and lower terraces. North of Stillwater, the vegetation along the river terraces changed, as indicated by Dr. Douglas Houghton, another member of Schoolcraft's party (Mason 1958): The river for a distance of 25 or 30 miles above the lake has a more desolate appearance. On either side are low ground subject to be overflowed in the fall and spring and at all times marshy. These are covered with a dense growth

Major Vegetation Patterns at the Time of Euro-American Settlement

[27]

St. Croix Moraine

Prairie in St. Paul Jetis--fur traders of mixed Fre~ch-Canadian and Ojibwe

M

or Cree ancestry who lived in settlements along the Red River in Manitoba and northwestern Minnesota— cam Dec on a prairie.ust west of the city limits of St. Paul in the mid-1800s during yearly visits to deliver buffalo skins and other furs and tc Dick up trade goods (see photc) (White and Wickers 19911. The prairie they camoed on had developed in a droughry area of sand deposited in southern Rarrsey County by merhvater from tne Grarlsburg sublobe (Patterson 1992).

A map of the Summit and Como areas of SI. Paul, 1859.

Metis among their oxcarts on a prairie near downtown S(. Paul, ca.1860.

Drairie in 1847, and it shows up in map 1 (inside front cover) as the largest patch of prairie in southeastern Ramsey County. The land surveyors also recorded a house and a plowed field within the prairie in 1847 (Trygg 1964). The 1859 map of the suburbs of St. Paul shows the actual extent of the prairie opening (the stippled area in the center). The prairie covered about seven or eight square miles in an area today bounded by Snellmg Avenue and Dale Street on the west and east, respectively, and by Summit and Como avenues on the south and north, respectively {the area is roughly bisected by Interstate 94). The road from St. Paul to the village of St. Anthony (at St. Anlhony Falls) passed through the middle of the

At the time (his photograph was taken, the prairie was an opening within the oak woodland-orushlanfl that covered much of Ramsey County. Indeed, the line of trees on the horizon in the photo delineated the end of the prairie ard the beginning of the woodland. General Land Office surveyors recorded the

prairie in 1859, as shown on the map. However, the Northern Pacific Railroad shown cutting through the northern edge of the prairie had not yet been built. The map also shows imaginary subdivisions covering the prairie. Within a few yea's of 1859, the boundaries of St. Paul had expanded to encompass the prairie (White and Wickers 19911.

[28]

Chapter 3

Cottage Grove Dissected Plain

Rosemount Outwash Plain

Fig. 3.5 Presettlement pattern of vegetation across the St. Croix moraine, Rosemount outwash plain, and Cottage Grove dissected plain. The vegetation is depicted along a hypothetical transect (AAxj stretching southeast across Washington Countyfrom White Bear Lake. The St. Croix moraine complex was dominated by oak woodland-brushland, while oak savanna and prairie were common on the Rosemount plain and Cottage Grove plain. The elevation changes along the transectfrom about 1,050feet at its high point on the St. Croix moraine to about 875 feet at its low point on the Rosemount outwash plain (see map 4, inside back cover).

of underbrush and some large trees of elm, ash, and soft maple [silver maple], back from these the bluffs rise to a great height. Higher up the river we saw trees of the butternut.

The floodplain forests described occurred in a narrow band adjacent to the river (see fig. 3.4). On the higher river terraces the floodplain forests gave way to hardwood swamps, tamarack swamps, and lowland hardwood forests on level, poorly drained ground (such as that near Goose Creek in Chisago County—see site 13 in part III) and maplebasswood forests and oak forests on higher, better-drained ground. The terraces north of Stillwater also had scattered patches of white pine, although some of these (for example, at Sunrise Bend) had been cut before the land along the river was surveyed in 1848 (Trygg 1964). Cottage Grove Dissected Plain The Cottage Grove dissected plain in southern Washington County was dominated in the south and west by prairie and in the northeast by oak savanna and oak woodlandbrushland. This description of Denmark Township in the General Land Office survey is typical:

The land in this township is high, dry and rolling. Soil good, loam, sand and gravel. The timber is mostly scrubby Bur, White and Black Oak scattered along thinly between the lake [Lake St. Croix] and the prairie on the west part of the township.

The prairies were probably mostly mesic prairies, because of the generally loamy soils of the Cottage Grove dissected plain, and were often described as "first rate prairies" (when on level land) and "second rate prairies" (on more rolling land). Savanna and woodland appear to have been most common along slopes where the Cottage Grove plain bordered the St. Croix River terraces (fig. 3.5) and in ravines within the Cottage Grove plain, such as that just northwest of Basswood Grove near Afton State Park. The Cottage Grove plain also contained dry bedrock bluff prairies on the numerous bedrock exposures along stream valleys and old glacial drainage channels. Bluff prairies were most common on south- and west-facing bluffs. Northeast-facing bluffs may have contained small thickets of oak and brush.

Major Vegetation Patterns at the Time of Euro-American Settlement

[29]

4. Influence of European-Americans The immigration of Euro-American settlers to the Region introduced a culture very different from that of the previous inhabitants. The pattern of consumption of plants and animals according to the local and immediate needs of a relatively small population was replaced by new patterns of use of the land and its plants and animals that were driven increasingly, as settlement proceeded, by speculation, by competition among businesses and landowners, and by trade with distant regions. This outcome was perhaps not surprising, as thousands of people migrated to the Region within a few decades, seeking wealth or at least a comfortable income from the resources of the Region.

Logging The first major wave of European-Americans to reach the Region were loggers looking for white pine. They began arriving in the 1840s and 1850s, after forests in Maine and other eastern states had been depleted of pine. White pine logging operations in east-central Minnesota centered on the St. Croix and Rum river valleys. The first commercial logging along the St. Croix River

began in the winter of 1837. A sawmill was constructed at Marine on St. Croix in 1839 (Swanholm 1978). By the early 1840s, 5 million feet of logs were passing annually through a log-sorting boom on the river at St. Croix Falls, destined for mills and markets downstream. By 1849, 75 million feet of logs were passing down the river each year. A large portion of this was rafted down the Mississippi to mills in Iowa, Illinois, and Missouri. By 1854, Stillwater had five sawmills supporting 1,000 loggers in the woods to the north. In 1857,140 million feet of logs passed through a new sorting boom on the St. Croix near Stillwater (Larson 1949, Swanholm 1978). Commercial logging along the Rum River did not begin until 1847, although earlier, during the 1820s and 1830s, soldiers from Fort Snelling had cut pine along the river to supply lumber to the fort (Goodrich 1905, White and Wickers 1991). In the winter of 1847, Daniel Stanchfield cruised the Rum River for pine. He reported seeing "pine that seventy mills could not cut in as many years" (Stanchfield 1901). Cutting began in earnest afterward (fig. 4.1). In the winter of 1848-49 Stanchfield cut 2.2 million feet of pine along the Rum and floated it downstream to be sawn at a Fig. 4.1 A logging camp on the Rum Rjver, ca. 1864.

Fig. 4.2 Construction on the Soo Line between Copas and Marine on St. Croix, ca. 1900. Logging began along the major rivers and streams in Minnesota, then spread inland as railroads were built in the 1860s and 1870s.

new mill at St. Anthony Falls. By 1855, a mill constructed at Anoka was said to be cutting 12,000 to 16,000 feet of pine daily, largely from the land along the Rum River. A second mill was soon put into operation, but even so the cutting could not keep up with the demand (Goodrich 1905). The next year, eight sawmills were in operation at St. Anthony Falls, sawing pine from along the Rum River and from upstream along the Mississippi. By 1870 the two sawmills in Anoka had a combined daily capacity of 175,000 feet, and in 1872 a new steam mill was built in Anoka with an annual capacity of 16 million feet (Goodrich 1905). During the peak years of white pine logging, mills were operating in the Region not only in Anoka, St. Anthony, and Stillwater, but also in smaller towns along the Rum River and its tributaries in Anoka and Isanti counties and along the St. Croix River in Chisago and Washington counties. Anoka claimed to be the largest lumbering town in Minnesota in the 1870s, but by the 1880s it became apparent that the pine along the Rum was being exhausted and logging was nearing its end (Goodrich 1905). The last sawmill in operation in Anoka shut down in 1889. The pine that Stanchfield had seen along the Rum River had been cleared in just 40 years. The pine forests along the St. Croix Valley were soon exhausted as well (fig. 4.2). In 1852, the editor of a St. Paul paper declared that "centuries will hardly exhaust the pines

above us," but as early as 1870, loggers began moving out of the valley, seeking more pine in the northern forests (Larson 1949). By the second decade of the 20th century the lumber mills of Minneapolis and the St. Croix River had shut down, and by 1937 the white pine industry had died throughout Minnesota. When logging was over in the area, 80 years after it began, 11 billion feet of logs had passed through the St. Croix boom, and hundreds of millions more had been milled at St. Anthony Falls and Anoka (Swanholm 1978). Most of this lumber came from the more extensive pine forests north of the Region, but substantial amounts were cut in northern Isanti and Chisago counties as well (Bergstrom and McGriff 1985, Larson 1949). It is reported that one man alone cut over 1 million board feet of pine around Stanchfield Lake in Isanti County. Other than the removal of white pine from the northern part of the Region, the direct impact of white pine logging on the landscape here can only be surmised. The plant and animal species compositions of the forests had not been documented before cutting began, so changes caused by logging remain unclear. Logging undoubtedly changed the composition of the soils, the rates of erosion, the fire regime, and the amount of sunlight reaching the ground, and these changes certainly caused corresponding changes in the vegetation.

Influence of European-Americans

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Agriculture Euro-American farming began in Minnesota in 1839, with the establishment of the Joseph Haskell farm in Afton Township in Washington County (Harvey 1980). Although farming began at about the same time as logging, it was secondary to logging as Minnesota's leading industry until the depletion of the white pine forests in the early 20th century. Nonetheless, the impact of agriculture on the landscape over the past 150 years has been much greater. The earliest farms were concentrated along the major rivers and their tributaries and along inland trails between population centers. They were mainly subsistence farms.

The early farmers had neither the technical means nor the financial incentive to cultivate all of their lands (City of Cottage Grove 1986, Letterman 1966, State Historic Preservation Office undated). By the 1860s, new technologies in plowing, planting, harvesting, and threshing machinery, the introduction of railroads, and increasing demand for wheat in North America and Europe fueled an expansion of farming across the Region and encouraged farmers to clear and cultivate more of their land. From the 1860s to the 1880s, wheat was the dominant cash crop in the Region (City of Cottage Grove 1986, Letterman 1966). After the 1880s, wheat cultivation declined, partly because of infestations of wheat rust disease and

Influence of Native Vegetation on Early Agriculture in Southern Washington County

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he earliest Euro-American farmers in the Region, many of whom were f