From the UNLV Special Collections Photograph Collection on Book Illustrations (PH-00170) -- Pass in the Sierra Nevada Mountains of California. Handwritten on verso: "Jackson, Donald, and Mary Lee Spence, editors. Expeditions of John Charles Fremont. Vol. 1, Urbana, Chicago, and London: University of Chicago Press, 1970. p. 636." [MLA8 citation format] "Pass in the Sierra Nevada of California".