A combination of Retriever and Courthouse soil types are generally found within this part of the watershed. Retriever soils are generally limited to elevations ranging from 3,300 ft. (1,006m) to 4,000 ft. (1,220m), while Courthouse soils are usually found at elevations of about 4,000 ft. (1,220m). These two soil types have been lumped into one unit here to accommodate the scale of this map.
Retriever: Retriever soils are highly calcareous and consist of very shallow or shallow, well-drained, typically very stony soils on undulating uplands, mesa tops, and moderately steep side slopes. They formed in material weathered from limestone and occur in areas where average annual precipitation is 11-13 inches. Plant cover is mainly canotia, Mormon tea, juniper, creosotebush, yucca, snakeweed, sideoats grama, and three-awn. Coarse fragments and outcrops of limestone are common and about half of the surface is barren. These soils have a pale-brown surface layer that is soft and has platy structure. The subsoil is light yellowish brown, soft when dry, and has blocky structure. The color of these soils ranges from pale brown and light brownish gray to reddish brown.
Courthouse: Courthouse soils are typically shallow to moderately deep, gently sloping to steep, and well-drained. They form in place over red sandstone of the Supai formation and contain a basalt component. They occur in areas where average annual precipitation is about 13 inches. Plant cover consists of catclaw, mesquite, juniper, turbinella oak, snakeweed, Rothrock grama, and sideoats grama. These soils are typicallly calcareous to the surface and have a red to reddish-brown surface layer of fine sandy loam that is soft when dry and friable when moist and has a blocky structure. The distinct subsoil is red gravelly heavy fine sandy loam that is friable when moist and has blocky structure. At a depth of 12 to 24 inches, light red, hard calcareous sandstone occurs.
Reference:
Williams, J.A.; Anderson, T.C., Jr. 1967. Soil Survey of Beaver Creek Area, Arizona. USDA Forest Service, Soil Conservation Service and Arizona Agriculture Experiment Station.