Cite

Ide's map of Montana / compiled & drawn by Reeder & Helmick.

MLA

Reeder, and Helmick. Ide's Map of Montana / Compiled & Drawn by Reeder & Helmick. Arthur W. Ide, 1890. https://collections.library.yale.edu/catalog/15814915.

APA, 6th edition

R., & H. (1890). Ide's map of Montana / compiled & drawn by Reeder & Helmick. [Maps]. Arthur W. Ide, https://collections.library.yale.edu/catalog/15814915.