All of these soils do not have a mollic epipedon. Hisle soils have a natric horizon and are in shallow depressions. Larvie soils are on ridges of a gilgai landscape and Conata and Norrest soils are on nearby convex slopes. Runoff is medium to very high depending on slope. Permeability is very slow.
Most areas are in native grass.
The native vegetation is western wheatgrass, green needlegrass, blue grama, buffalograss, sedges, and forbs. Mellette County, South Dakota, 1971.