The Dworshak series consists of very deep, well drained soils that formed in volcanic ash and loess over residuum from metamorphic rock. Dworshak soils are on mountain slopes and have slopes of 5 to 50 percent.
Permeability is moderately slow.
Dworshak ashy silt loam - on a southeast facing convex slope of 15 percent at an elevation of 3,500 feet, forested. USGS Southwick Quadrangle. Average annual soil temperature - 43 to 45 degrees F. Frigid temperature regime. Soil moisture control section - dry for 20 to 45 consecutive days in late summer and early fall. Udic moisture regime.