Sub-locations
| Name | Sites | Samples |
|---|---|---|
| Bennett County | 1 | 2 |
| Brookings County | 2 | 15 |
| Brule County | 2 | 20 |
| Buffalo County | 5 | 14 |
| Butte County | 2 | 12 |
| Campbell County | 7 | 35 |
| Charles Mix County | 2 | 2 |
| Clay County | 2 | 8 |
| Corson County | 7 | 30 |
| Custer County | 39 | 122 |
| Davison County | 1 | 10 |
| Deuel County | 1 | 5 |
| Dewey County | 0 | 0 |
| Fall River County | 25 | 74 |
| Gregory County | 0 | 0 |
| Haakon County | 1 | 5 |
| Hand County | 1 | 1 |
| Harding County | 14 | 30 |
| Hughes County | 10 | 34 |
| Hutchinson County | 3 | 4 |
| Lake County | 1 | 2 |
| Lawrence County | 7 | 14 |
| Lincoln County | 1 | 3 |
| Lyman County | 17 | 47 |
| Meade County | 7 | 15 |