Cite

Down the zig-zags from Whitney Pass, called the Staircase or The Ladder. 167

MLA

Down the Zig-Zags from Whitney Pass, Called the Staircase or The Ladder. 167. 0AD. https://collections.library.yale.edu/catalog/2016914.

APA, 6th edition

Down the zig-zags from Whitney Pass, called the Staircase or The Ladder. 167. (0 C.E.). [Photographic prints, Photographs, Stereographs]. https://collections.library.yale.edu/catalog/2016914.