Minnesota Master Naturalist

Big Woods, Big Rivers

The official name for the ecological province called Big Woods, Big Rivers by the Minnesota Master Naturalist Program is the Eastern Broadleaf Forest. It reaches from Minnesota and stretches southeast to Arkansas encompassing portions of twelve states along the way. The Big Woods, Big Rivers make a diagonal sash across the state of Minnesota, starting at the Northwest corner of the state with a narrow band and widening out in the southeast. It takes in approximately 12 million acres of the state.

Three of the largest rivers in the state are found in this region, the Mississippi, the St. Croix, and the Minnesota. All three were formed during the last glacial period when the huge glacial lakes had formed and were draining into these river channels. The Southeast was not covered by the last glacier and provides a great view into earlier time periods.

Many plant species are at the edge of their range in this biome. Making it a unique transition zone where evapotranspiration and precipitation are nearly equal. Temperature and rainfall increase as you move toward the southeast portion of the biome.

The Tallgrass Aspen Parklands are included in this biome within the Minnesota Master Naturalist Program. The Tallgrass Aspen Parklands, are a cold and dry region that forms a transition between the prairie to the west and the coniferous boreal forest to the east. The biome comprises about 3 million acres in our state.

Source: Minnesota DNR