Burt, William (Surveyor), Mullett, John, 1786-1862 (1840). 32N 01W - Survey Map of Corwith Township, Otsego County [Michigan]. Department of Natural Resources. https://michigan.access.preservica.com/uncategorized/IO_35b8d71e-479f-4ab8-a2fd-02b05c6608e7 (map)