Source: Topographical map of the county of Penobscot, Maine / field work under the direction of L.H. Eaton ; from surveys under the direction of H.F. Walling ; engraved, printed, colored & mounted at H.F. Walling's map establishment. New York: Lee & Marsh, Publishers, 1859. Library of Congress, Geography and Map Division. [Digital ID: g3733p la000272b]