SF-308. Snowshoe Trail and Big White Pine.
MLA
McClintock, Walter, 1870-1949. SF-308. Snowshoe Trail and Big White Pine.. Box 146, folder 7748. undated. https://collections.library.yale.edu/catalog/10453893.
APA, 6th edition
McClintock, Walter, 1870-1949. (["Box 146, folder 7748"])(undated)[SF-308. Snowshoe Trail and Big White Pine.]. https://collections.library.yale.edu/catalog/10453893.