| County Subdivision | 1990 Population |
| Alcona township | 906 |
| Caledonia township | 987 |
| Curtis township | 1128 |
| Greenbush township | 1373 |
| Gustin township | 823 |
| Harrisville city | 470 |
| Harrisville township | 1315 |
| Hawes township | 1035 |
| Haynes township | 549 |
| Mikado township | 852 |
| Millen township | 417 |
| Mitchell township | 290 |