Pit soils have moist chroma of 1 or less in the upper part of the A horizon, and are poorly drained. Terwilliger soils have an ochric epipedon and a fine argillic horizon. Lassen soils are used primarily for livestock grazing. Some cultivated areas are used for the production of dryland and irrigated small grains, hay and pasture. The vegetation is principally bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass.
Some areas have a very few scattered juniper and black oak or white oak.
Other areas may be dominantly medusahead. Lassen soils are moderately extensive in north-central California and occur in large bodies. MLRA is 21.