Presettlement vegetation ranged from the abundant bur oak savanna, to maple-basswood forest and upland, tallgrass prairies. Today agriculture has claimed much of this landscape, with urban development encroaching from the north. Wetland preservation and restoration and protection of natural areas of high quality have become critical conservation issues. Rochester Plateau Loess covers this old bedrock plateau along the eastern portion of this area, and also much of the gently rolling glacial till plain in the west. Cushioned only thinly with till, the bedrock of dolomite, limestone, sandstone, and shale is exposed along the valley walls of the Mississippi River.
Few lakes occur, but the headwaters of several major rivers are found here.
Coldwater trout streams are a prime feature of the eastern portion. Tallgrass prairie and bur oak savanna grew here before settlement, amidst the hazards of fire, high winds, and ice storms. Groundwater quality, now influenced by agricultural activity, and loss of forest communities are primary conservation issues. The old plateau in this landscape gives way to deeply eroded river valleys along the Mississippi. There the tributaries, loaded with accumulated water and sediment, tumble down the 600-foot relief to the Mississippi River, eroding rugged sedimentary outcrops along the steep ravines.