Cite

Colorado : city-county state map / [by] Rand McNally.

MLA

McNally, Rand, and Company. Colorado : City-County State Map / [by] Rand McNally. The Company, 0AD. https://collections.library.yale.edu/catalog/15818453.

APA, 6th edition

McNally, R., & C. (0 C.E.). Colorado : city-county state map / [by] Rand McNally. [Maps]. The Company, https://collections.library.yale.edu/catalog/15818453.