This image was acquired from
flickr. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
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