Route map, Juneau to Porcupine River, Alaska.
MLA
Coast, U. S., and Geodetic Survey. Route Map, Juneau to Porcupine River, Alaska. U.S. Coast and Geodetic Survey, 1898. https://collections.library.yale.edu/catalog/15821750.
APA, 6th edition
Coast, U. S., & Survey, G. (1898). Route map, Juneau to Porcupine River, Alaska. [Topographic maps]. U.S. Coast and Geodetic Survey, https://collections.library.yale.edu/catalog/15821750.