This region bridges the transition zone between prairie to the west and true forest to the east. Pre-settlement vegetation included bur oak savannas, brush prairie and oak forest. Tallgrass prairie occupied the least dissected portions and ground cover of open savannas. Sugar maple-basswood forest occupied the steeper sites. Most of the level to rolling topography is intensively farmed.
Animal agriculture is intensive in many areas resulting in erosion and over grazing.
This region gets its name from the mosaic of aspen groves, prairie, and wetlands. Low dunes, beach ridges, wet swales and shrub-aspen dominate. Livestock grazing, gravel mining, and row crop agriculture are the primary land uses. Fire suppression has allowed much of the brush prairie to be converted to aspen parklands. Prescribed burning and timber harvest will be practiced to restore brush prairie and benefit species diversity and upland bird habitat.