Stereo World article on Carleton Watkins (March - April 1977) Courtesy of the Central Pacific Railroad Photographic History Museum and the National Stereoscopic Association.
Carleton Watkins wiki Wikipedia page with Carleton Watkins biography, links and references.
Picturing Progress
Carleton Watkins's 1867 Stereoviews of the Columbia River Gorge(Fall 2008) Terry Toedtemeier and Megan K. Friedel co-wrote this article on Watkins's stereoviews of the Columbia River
Gorge, published in Fall 2008 by the Oregon Historical Quarterly. The article won the 2009 Joel Palmer Award, Honorable Mention.