The soils formed in moderately thin, noncalcareous eolian materials containing a high proportion of very fine sand and deposited over hard sandstone. At the type location the mean annual precipitation is about 17 inches with nearly equal precipitation in all months. These are the Mughouse soils and the competing Roubideau soils. Mughouse soils have an argillic horizon with more than 35 percent clay and lack any fragipan-like horizons. Used principally as grazing land or for recreation.
Native vegetation is pinyon, juniper, oak brush, sage, western wheatgrass, and bluegrass.
The series is of small extent. Mesa Verde Area, Montezuma County, Colorado, 1965.