Cite

Ascending grade Marshall Pass, near summit Rocky Mts

MLA

Ascending Grade Marshall Pass, near Summit Rocky Mts. 1892. https://collections.library.yale.edu/catalog/2014389.

APA, 6th edition

Ascending grade Marshall Pass, near summit Rocky Mts. (1892). [Card photographs, Photographic prints, Photographs, Snapshots]. https://collections.library.yale.edu/catalog/2014389.