The Schnebly Hill Formation is a dark red Permian sandstone on the Colorado Plateau near Sedona, Arizona, and a major source of the region’s famous red-rock scenery. Usually about 800 to 1,000 feet thick, it lies between the younger Coconino Sandstone and the older Hermit Formation, with the Supai Group nearby in the regional sequence. Its deep red color comes from hematite, an iron oxide that stains the rock and makes it stand out in cliffs and buttes. Divided into the Bell Rock, Fort Apache, and Sycamore Pass members, it is both an important geological unit in northern Arizona and a landform closely tied to Sedona’s identity.