Mesic tallgrass prairie, seen in the foreground, was much less extensive than wet prairie on the poorly drained clay plain. Drainage has allowed most of this landscape to be converted to agriculture. Minnesota Department of Natural Resources photo by D.S. Wovcha. Drainage is to the north via the Red River and its tributaries. Poorly drained lacustrine clays, sands, and gravels, primarily Mollisols.
Saline soils are locally present.
At the time of settlement, almost the entire section was tall-grass prairie. Narrow, forested floodplains were originally present along larger streams. Bison grazing and ant activity caused important fauna modifications of the vegetation and soils, respectively. The interbeach zone of Glacial Lake Agassiz contains some of the largest remaining tracts of native prairie vegetation, primarily due to a combination of locally steep dunes, gravelly beach ridges, and poorly drained interbeach areas. The vegetation of the interbeach zone changes to aspen or oak woodlands.