These are the Penistaja , Plack , Sampson and Tortugas soils. Penistaja soils lack a mollic epipedon. Plack soils are 20 inches to a petrocalcic horizon. Sampson soils have a thicker mollic epipedon. Tortugas soils have a lithic contact within 20 inches.
Principal use is rangeland.
The present vegetation is western wheatgrass, sideoats grama, blue grama, wolftail, and bottlebrush squirreltail. Reventon soils are of small extent in southcentral New Mexico.