Northern Prairie Wildlife Research Center
ELEVATION: 1,420 to 1,770 feet (432 to 540 m).
AREA: 785 square miles (2,033 sq km).
CLIMATE: See subsection.
BEDROCK GEOLOGY: Outcrops of Sioux quartzite are exposed in northern Rock County and southern Pipestone County (Olsen and Mossler 1982, Morey 1976, Wright 1972); but over much of the sub-subsection, glacial drift is 200 to 400 feet thick. Beneath this drift, upper Precambrian Sioux quartzite is the most common bedrock, followed by Cretaceous shale, sandstone, and clay (Morey 1976).
LANDFORMS: Loess-capped till plain. The loess mantle has smoothed the topography of the underlying till plain, creating a landscape with long, gentle slopes (University of Minnesota et al. 1981a). The southwestern part of the coteau consists of glacial drift covered with loess 4 to 10 feet thick (Hargrave 1992); the loess thickens to the southwest and probably originated from the outwash deposits of the Big Sioux River (Wright 1972).
LAKES AND STREAMS: Few wetlands because of the well-developed drainage system.
SOILS: Cummins and Grigal (1981) map most of the sub-subsection as dry prairie soils. Soils are classified as Mollisols (Aquolls, Udolls, Borolls, and Ustolls).
PRESETTLEMENT VEGETATION: The original vegetation was almost entirely tallgrass prairie, with only small areas of wet prairie. Forest was present along the Rock River.
NATURAL DISTURBANCE: Fire and drought maintained the prairie.
PRESENT VEGETATION AND LAND USE: The land is used primarily for crop land; little or no woodland and pasture occurs (University of Minnesota et al. 1981a).
RARE PLANTS: Aristida purpurea var. longiseta (red three-awn), Bacopa rotundifolia (water-hyssop), Buchloe dactyloides (buffalo grass), Cyperus acuminatus (umbrella-sedge), Heteranthera limosa (mud plantain), Isoetes melanopoda (a species of quillwort), Limosella aquatica (mudwort), Marsilea vestita (hairy water clover), Myosurus minimus (mousetail), Opuntia macrorhiza (plains prickly pear), Plantago elongata (slender plantain), Platanthera praeclara (western prairie fringed orchid), Schedonnardus paniculatus (tumblegrass), Solidago mollis (soft goldenrod), Tillaea aquatica (pigmyweed), Verbena simplex (narrow-leaved vervain).
RARE ANIMALS: Birds: Athene cunicularia (burrowing owl), Calcarius mccownii (McCown's longspur (extirpated)); Amphibians: Acris crepitans blanchardi (Blanchard's cricket frog); Reptiles: Tropidoclonion lineatum (lined snake); Fish: Notropis topeka (Topeka shiner), Fundulus sciadicus (plains topminnow); Insects: Hesperia dacotae (Dakota skipper).
NATURAL AREAS: State Natural Areas: Blue Mounds State Park, Pipestone National Monument, Split Rock Creek State Park, Prairie Coteau Scientific and Natural Area, Pipestone County; The Nature Conservancy Preserves: Hole-in-the-Mountain Prairie.
PUBLIC LAND MANAGERS: See subsection.
CONSERVATION CONCERNS: Overgrazing, gravel mining, and conversion of the few areas presently supporting native plant communities to cropland.
BOUNDARIES: The boundary is defined by pre-Wisconsinan drift, traditionally treated as Kansan drift, as mapped by Hobbs and Goebel (1982).