Art Source International: Historic Colorado PhotographsThis company has accumulated over 2000 original glass plates, negatives and original photographs of Colorado dating from around 1865 to 1940. Fee-based collection. This site includes photos by well known western photographers such as William Henry Jackson, J.B. Sturtevant (a.k.a. Rocky Mountain Joe), Louis McClure, in addition to many one of a kind images. Many of the photographs illustrate historic Boulder, Denver, and Aspen as well as over 50 other Colorado cities