Cite

Reconnaissance map of the Northern Selkirk Mountains and the Big Bend of the Columbia River, British Columbia / by Howard Palmer and Robert H. Chapman.

MLA

Palmer, Howard. Reconnaissance Map of the Northern Selkirk Mountains and the Big Bend of the Columbia River, British Columbia / by Howard Palmer and Robert H. Chapman. drawn and printed at the Surveyor General's Office, 1915. https://collections.library.yale.edu/catalog/15536325.

APA, 6th edition

Palmer, H. (1915). Reconnaissance map of the Northern Selkirk Mountains and the Big Bend of the Columbia River, British Columbia / by Howard Palmer and Robert H. Chapman. [Maps]. drawn and printed at the Surveyor General's Office, https://collections.library.yale.edu/catalog/15536325.