Frontier Sandstone and Mowry Shale Members of Mancos Shale, and Dakota Sandstone
Sandstone. Early Cretaceous, about 122 to 100 million years old. 1 crag on this site has its map point on it.
The map groups these named formations into this unit: Frontier Sandstone Member, Mowry Shale Member, Dakota Sandstone.
What the map says
Locally includes, at base, Burro Canyon Fm (shale and sandstone) or, in western Moffat County, Cedar Mountain Fm (conglomerate and shale) Lithology: sandstone, shale, minor conglomerate.
1:500,000 sheet: Horton and others, 2017, U.S. Geological Survey Data Series 1052 (1 crag). A contact line at that scale is about 500 m wide on the ground.
Served by Macrostrat (CC BY 4.0). The wording is the map's own, quoted as a fact about the mapped unit, not about any one wall.