Cite

Desert Riders trail map / by D.V. Garstin & N.K. Blanchard.

MLA

Garstin, D. V. Desert Riders Trail Map / by D.V. Garstin & N.K. Blanchard. U.S. Geological Survey?], 1965. https://collections.library.yale.edu/catalog/15821522.

APA, 6th edition

Garstin, D. V. (1965). Desert Riders trail map / by D.V. Garstin & N.K. Blanchard. [Maps]. U.S. Geological Survey?], https://collections.library.yale.edu/catalog/15821522.