They formed in stony and cobbly and gravelly residuum from andesite and basalt. The climate is semiarid with warm, dry summers and moist, cold winters. The mean annual precipitation is 12 to 18 inches. The frost free season is about 60 to 90 days. These are the Borda and Millich soils.
Borda soils have ochric epipedons and fine textured argillic horizons.
Millich soils have fine textured argillic horizons. The vegetation is mainly big sagebrush, bitterbrush, bluegrass, cheatgrass, squirreltail, and rabbitbrush with scattered pinyon pine and juniper. The soils are of small extent. MLRA 26, 29. Douglas County, Nevada, 1973.