Cite

(MONTANA) [Anon.] Map of a Portion of Montana Territory.

MLA

(MONTANA) [Anon.] Map of a Portion of Montana Territory. 1886. https://collections.library.yale.edu/catalog/2016955.

APA, 6th edition

(MONTANA) [Anon.] Map of a Portion of Montana Territory. (1886). [Maps]. https://collections.library.yale.edu/catalog/2016955.