Excavation contractors in Coconino County, AZ

The Colorado Plateau counties of Apache, Coconino, and Navajo sit on flat-lying sandstone and shale under thin soils. SSURGO mapping shows Navajo and rock outcrop among the dominant units, with Aridisols, Mollisols, and Entisols on the surfaces. Bedrock is close enough that footings and trenches meet rock within a few feet on many sites. Shale layers slake and slide once exposed, so cut faces ravel and slump. Sandy surface soils cave when cut and blow when dry, so loose sand moves off open grading. Rock outcrop is common across the plateau, and the thin soil lies directly on the bedrock in many places. Soils here hold little water, and the shallow rock leaves little room for deep excavation or stable fill on the mesas.