Sub-locations
| Name | Sites | Samples |
|---|---|---|
| Logan County | 2 | 4 |
| Lonoke County | 2 | 22 |
| Madison County | 4 | 10 |
| Marion County | 2 | 10 |
| Miller County | 2 | 42 |
| Mississippi County | 16 | 58 |
| Montgomery County | 6 | 25 |
| Newton County | 5 | 17 |
| Ouachita County | 1 | 10 |
| Phillips County | 5 | 14 |
| Poinsett County | 9 | 77 |
| Polk County | 1 | 3 |
| Prairie County | 1 | 2 |
| Pulaski County | 3 | 11 |
| Randolph County | 2 | 4 |
| Saline County | 3 | 8 |
| Scott County | 1 | 2 |
| Searcy County | 3 | 4 |
| Sebastian County | 1 | 19 |
| Sevier County | 1 | 3 |
| St. Francis County | 2 | 5 |
| Stone County | 1 | 5 |
| Union County | 1 | 3 |
| Washington County | 7 | 22 |
| Yell County | 2 | 4 |