Burt, William Austin, 1792-1858, Houghton, Douglass, 1809-1845 (1845). 57N 29W - Survey Map of Grant Township, Keweenaw County [Michigan]. Department of Natural Resources. https://michigan.access.preservica.com/uncategorized/IO_5a5ade16-2ed6-4b79-a59a-864e6b1976f9 (map)