Keywords: stereoscopic stereophotography stereophotographs historical usgs history geology mapping black and white blackandwhite bnw stereograph outdoor landscape crag cliff blackandwhite black and white Grand Canyon National Park, Arizona. First Granite Gorge. September 1872. U.S. Geographical and Geological Survey of the Rocky Mountain Region (Powell Survey). Stereoscopic view. Negative cracked. Grand Canyon National Park, Arizona. First Granite Gorge. September 1872. U.S. Geographical and Geological Survey of the Rocky Mountain Region (Powell Survey). Stereoscopic view. Negative cracked. |