Slopes are 0 to 15 percent. The soils formed in rhyolitic volcanic ash. The mean annual precipitation is 6 to 12 inches, mostly as snow. Mean annual snowfall is 40 to 100 inches. The frost-free season is 110 to 150 days.
Alamedawell soils are ashy over loamy.
Buscones soils are 20 to 40 inches deep over soft tuff. Deepwell soils formed in aeolian dunes consisting mostly of fine sand, and lack gravel. Pizona soils are 40 to 60 inch deep with more than 35 percent rock fragments in their argillic horizons. Sherwin soils are shallow over hard tuff. Wellington and Sawavu soils have duripans.