MLA

Press, A. B. Hirschfeld. Wyoming, 1977, Official Highway Map / Prepared by The A.B. Hirschfeld Press. Wyoming State Highway Commission, 1977. https://collections.library.yale.edu/catalog/15818404.

APA, 6th edition

Press, A. B. H. (1977). Wyoming, 1977, official highway map / prepared by The A.B. Hirschfeld Press. [Maps]. Wyoming State Highway Commission, https://collections.library.yale.edu/catalog/15818404.