Swanboy soils are on fans and flats. They have salts within 10 inches of the dispersed surface. Runoff is medium to very high depending on slope. Permeability is very slow, except after dry periods when the initial intake into cracks is rapid. Wheat, sorghum, and alfalfa are the principal crops when cultivated.
Native grasses are mostly western wheatgrass, green needlegrass, buffalograss, and blue grama.
The series is extensive. Butte County, South Dakota, 1970.