Sub-locations
| Name | Sites | Samples |
|---|---|---|
| Harlan County | 5 | 26 |
| Hitchcock County | 1 | 1 |
| Hooker County | 2 | 10 |
| Howard County | 4 | 17 |
| Keith County | 2 | 3 |
| Knox County | 1 | 3 |
| Lancaster County | 1 | 1 |
| Lincoln County | 0 | 0 |
| Loup County | 1 | 4 |
| Madison County | 1 | 1 |
| Merrick County | 2 | 5 |
| Morrill County | 1 | 1 |
| Nance County | 2 | 5 |
| Nemaha County | 2 | 5 |
| Otoe County | 2 | 6 |
| Pawnee County | 1 | 2 |
| Perkins County | 1 | 0 |
| Platte County | 3 | 6 |
| Red Willow County | 2 | 7 |
| Richardson County | 4 | 19 |
| Sarpy County | 4 | 24 |
| Saunders County | 2 | 3 |
| Scotts Bluff County | 2 | 16 |
| Sherman County | 3 | 8 |
| Sioux County | 9 | 66 |