Founded in 1843, Ontonagon County is one of 83 counties in the state of Michigan. Historically, Ontonagon County was formed from parts of Chippewa County and Mackinac County. The city of Ontonagon is the county seat. With FIPS code of 131, Ontonagon County has a population of 5,868 and area of 3,741 square miles (9,689 km2).
List of all cities in Ontonagon County, MI alphabetically
| City/Town | Postal Code | Area Code |
| Bergland, MI | 49910 | 906 |
| Bruce Crossing, MI | 49912 | 906 |
| Ewen, MI | 49925 | 906 |
| Greenland, MI | 49929 | 906 |
| Kenton, MI | 49967 | 906 |
| Mass City, MI | 49948 | 906 |
| Ontonagon, MI | 49953 | 906 |
| Rockland, MI | 49960 | 906 |
| Trout Creek, MI | 49967 | 906 |
| White Pine, MI | 49971 | 906 |