, Black and white photograph of the Oregon Trail at Rocky Ridge located approximately 20 miles east..., , This file is derived from a 600 dpi, high-resolution (3340 x 2765 ppi, 8-bit grayscale) uncompres...,
, Black and white photograph of the Oregon Trail at Rocky Ridge located approximately 20 miles east..., , This file is derived from a 600 dpi, high-resolution (3340 x 2765 ppi, 8-bit grayscale) uncompres...,