I. An Ever Changing Landscape

12,000 years ago

Early arrivals found a forest of thick spruce and bogs in what is now southwestern Minnesota. To the north and east, they found wet tundra with dwarfed spruce and, to the north and west, a huge glacial lake.

10,000 years ago

Minnesota's climate warmed, glacial lakes drained and spruce, fir and tundra landscapes were replaced by a growing deciduous forest of birch, aspen and coniferous trees, such as balsam fir. As the land continued to warm, those forests were replaced by huge stands of white pine, red pine and jack pine. By 8,000 years ago, those trees were giving way to oaks, maples and beech.

Prairies began to emerge in the southwestern part of Minnesota and people followed the game northward into the forests.

7,000 years ago

The climate had warmed so much that prairie ecosystems, called oak savannas, could be found occasionally as far north as what is now the U.S.-Canadian border.

People living on the edges of forests and prairies hunted and gathered food and fished the lakes. Living in small groups and extended families, their impact on the forest was limited. They may have practiced selective forestry techniques, cutting non-maple trees to favor sugar maples and burning forested islands to spur berry growth and increase animal populations.

5,000 years ago

The Minnesota climate and the forest ecosystem began another slow change. The climate cooled, and northern prairies receded southward. The northern forests, called the North Woods, evolved once again into hardwoods and eventually into vast stands of red, white and jack pines, white and black spruce, balsam fir, tamarack and white cedar interspersed with mixed hardwoods of birch, maple, oak, elm, aspen, and basswood.

This mosaic of woodlands yielded in the central and southeastern portions of Minnesota to the Big Woods, a belt of hardwood trees dominated by oak, elm, basswood, maple, black walnut and butternut.

A sea of wild grass often six feet tall surrounded the forests with big blue stem, side oats gramma and blue-joint grasses. As native populations grew, their sophistication in landscape manipulation grew as well. People managed both forests and fields through agriculture and fire to encourage different plants and animals.

4,000 years ago to modern era

Major climate change slowed and the balance between field and forest remained relatively steady until the present day. European Americans entered these Tall Grass Prairies, Big Woods and North Woods. With increased populations, advancing technology, and a different cultural attitude, they changed the forests and fields again.