Most of the bottomlands along the Middle Fork are sandy and relatively well drained, but there are 332 acres of forested wetlands in the corridor which support 116 species of wildlife (mostly birds). The largest is in Collison Marsh where an artesian well runs through midsummer, and a series of beaver dams provides homes for this mud turtle and a host of other wetland species. The ever-expanding complex of beaver dams provides a fresh supply of dead trees that support woodpeckers and nesting sites for wading birds. Unique wildflowers include skunk cabbage, blue flag iris, and a variety of grasses.