Quick view Compare Cross, Whitman & Hole, Allen D.; Engineer Mountain Folio, Colorado. Geologic Atlas Folio #171. Washington D. C., U.S. Geological Survey, 1910.
Quick view Compare Cross, Whitman, et.al; USGS La Plata Colorado Folio. USGS Geologic Atlas of the United States, Folio 60, Washington, D.C., 1899.