Keywords: stereoscopic stereophotography stereophotographs historical usgs history geology mapping black and white blackandwhite bnw stereograph blackandwhite monochrome forest landscape outdoor tree plant black and white Yellowstone National Park, Wyoming. Granite boulder near Yellowstone Canyon. U.S. Geological and Geographical Survey of the Territories (Hayden Survey) Yellowstone National Park, Wyoming. Granite boulder near Yellowstone Canyon. U.S. Geological and Geographical Survey of the Territories (Hayden Survey) |