Several helpful gazetteers of Wisconsin have been published. Some of the most helpful are:
Hale, James B.W. Wisconsin Post Office Handbook. Revised edition. (Not available at the Family History Library.) Available from the Wisconsin Postal History Society, 5401 Raymond Rd., Madison, WI 53711.
Hunt, John Warren. Wisconsin Gazetteer. Madison, Wisconsiin: B. Brown, 1853. (FHL book 977.5 E5h; film 897468; fiche 6051150.)
Moertl, Frank. Wisconsin; Its Territorial and Statehood Post Offices, 1993. (Not available at the Family History Library.) Available from the Wisconsin Postal History Society, see above. This has detailed maps and descriptions showing the location of each post office.
Wisconsin Gazetteer. Wilmington, Delaware: American Historical Publications, Inc., 1991. (FHL book 977.5 E5w.)