Cite

State Highway Department's map of the state of Oregon showing main traveled automobile roads / compiled and published by the Oregon State Highway Commission.

MLA

Commission, Oregon State Highway. State Highway Department's Map of the State of Oregon Showing Main Traveled Automobile Roads / Compiled and Published by the Oregon State Highway Commission. Oregon State Highway Commission, 1930. https://collections.library.yale.edu/catalog/15821616.

APA, 6th edition

Commission, O. S. H. (1930). State Highway Department's map of the state of Oregon showing main traveled automobile roads / compiled and published by the Oregon State Highway Commission. [Road maps]. Oregon State Highway Commission, https://collections.library.yale.edu/catalog/15821616.