Sub-locations
| Name | Sites | Samples |
|---|---|---|
| Alcona County | 1 | 1 |
| Alger County | 8 | 13 |
| Allegan County | 10 | 31 |
| Antrim County | 1 | 5 |
| Arenac County | 1 | 1 |
| Baraga County | 1 | 3 |
| Bay County | 6 | 25 |
| Benzie County | 1 | 3 |
| Berrien County | 11 | 44 |
| Branch County | 1 | 1 |
| Calhoun County | 1 | 2 |
| Cass County | 3 | 2 |
| Charlevoix County | 2 | 11 |
| Cheboygan County | 3 | 2 |
| Chippewa County | 3 | 14 |
| Clinton County | 1 | 2 |
| Delta County | 4 | 16 |
| Eaton County | 0 | 0 |
| Emmet County | 2 | 13 |
| Genesee County | 3 | 5 |
| Grand Traverse County | 2 | 5 |
| Gratiot County | 6 | 15 |
| Houghton County | 1 | 1 |
| Huron County | 3 | 9 |
| Ingham County | 4 | 4 |