They formed in clayey alluvium. The mean annual temperature ranges from 45 to 52 degrees F, and the mean annual precipitation ranges from 18 to 26 inches. These are the Clamo , Lamo , Salmo , and Wann soils. The Clamo and Lamo soils are on slightly higher areas. Clamo soils do not have carbonate in the upper part of the solum and contain less salts.
Lamo soils are fine-silty and contain less salts.
Salmo soils are fine-silty and are on similar landscapes. Wann soils are coarse-loamy and are on higher parts of the floodplain. Poorly drained or very poorly drained. Surface runoff is very slow or ponded. Permeability is slow or very slow.