Denver Fm or lower part of Dawson Arkose
Sandstone. Phanerozoic, about 67 to 57 million years old. 2 crags on this site have their map point on it.
The map groups these named formations into this unit: Denver Formation, Dawson Arkose.
What the map says
Arkosic sandstone, shale, mudstone, conglomerate, and local coal beds Lithology: arkose, shale, mudstone, minor conglomerate, coal.
1:500,000 sheet: Horton and others, 2017, U.S. Geological Survey Data Series 1052 (2 crags). 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.