It has 0 to 75 percent paragravels increasing with depth. The 2Bsm horizon is weakly or moderately cemented by iron, aluminum and manganese. These are the Elwell , Oyhut and Hoko series. Elwell soils are frigid. Hoko soils are medial-skeletal.
Oyhut soils have hard rock fragments.
These soils are on till plains, mountain sides and mountain valleys at elevations of 30 to 800 feet. Slopes are 1 to 65 percent. They formed in alpine glacial till that include local Olympic basalt, graywacke, shales, and argillite. Copalis soils are in a humid climate with relatively cool summers and mild, wet winters. The frost-free period is 140 to 210 days.