Cite

Idaho, Montana, Wyoming / [prepared for] Sinclair.

MLA

McNally, Rand, and Company. Idaho, Montana, Wyoming / [Prepared for] Sinclair. Rand McNally, 0AD. https://collections.library.yale.edu/catalog/15818334.

APA, 6th edition

McNally, R., & C. (0 C.E.). Idaho, Montana, Wyoming / [prepared for] Sinclair. [Maps]. Rand McNally, https://collections.library.yale.edu/catalog/15818334.