MLA

McClintock, Walter, 1870-1949. F6809. My Horse Picketed Near Lodges. Twin Peaks. Clouds Settling on Mountains Before Storms.. Box 138, folder 6515. 1906 Fall. https://collections.library.yale.edu/catalog/10452201.

APA, 6th edition

McClintock, Walter, 1870-1949. (["Box 138, folder 6515"])(1906 Fall)[F6809. My Horse Picketed Near Lodges. Twin Peaks. Clouds Settling on Mountains Before Storms.]. https://collections.library.yale.edu/catalog/10452201.