White River Fm or Group
Cenozoic, about 35 to 23 million years old. 1 crag on this site has its map point on it.
What the map says
East: Ashy claystone and sandstone. Includes Castle Rock Conglomerate in region southeast of Denver. Northwest: Ashy claystone in North Park Lithology: sandstone, claystone, 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.