Research Collection. 1910-1969. 2 linear feet. The collection centers solely on Rankin's research on the life and work of Charles M. Russell. One series, General Correspondence, constitutes eighty percent of the collection. It also is the most valuable for research on Russell and on ranching and cowboy life in the open range era. Many friends and acquaintances of Russell corresponded extensively with Rankin, and their reminiscences would have been the basis of his book. Other correspondents discussed the Russell paintings and sculpture in their collections. The letters also reflect the provenance of much of the artist's work, kinds of shows that it appeared in, and methods by which it was acquired. The Research Notes series of the collection contains listings of paintings, notes on interviews, and transcriptions of letters of Russell and others. Also, there are several photographs of pieces of Russell's work owned by various institutions and individuals at that time. The collection is completed by a series of Clippings gathered by Rankin which generally concern Russell's life. Selected photographs were separated to the Photograph Archives.