Burt, William (Surveyor), Burt, William Austin, 1792-1858 (1847). 49N 46W - Survey Map of Ironwood Township, Gogebic County [Michigan]. Department of Natural Resources. https://michigan.access.preservica.com/uncategorized/IO_eb5e409b-f7e6-422a-82f9-016472806f5f (map)