MLA

of Highways, Colorado. Dept. Travel Map of Colorado for 1963 / Prepared by Colorado Department of Highways, Planning and Research Division. The Department, 1963. https://collections.library.yale.edu/catalog/15818470.

APA, 6th edition

of Highways, C. D. (1963). Travel map of Colorado for 1963 / prepared by Colorado Department of Highways, Planning and Research Division. [Road maps]. The Department, https://collections.library.yale.edu/catalog/15818470.