Keywords: stereoscopic stereophotography stereophotographs historical usgs history geology mapping black and white blackandwhite bnw stereograph blackandwhite monochrome black and white Yellowstone National Park, Wyoming. Hot Springs cone in Yellowstone Lake near the Thumb.U.S. Geological and Geographical Survey of the Territories (Hayden Survey). Stereoscopic view Yellowstone National Park, Wyoming. Hot Springs cone in Yellowstone Lake near the Thumb.U.S. Geological and Geographical Survey of the Territories (Hayden Survey). Stereoscopic view |