Sub-locations
| Name | Sites | Samples |
|---|---|---|
| Baker County | 8 | 19 |
| Benton County | 3 | 8 |
| Clackamas County | 2 | 1 |
| Clatsop County | 28 | 40 |
| Columbia County | 7 | 57 |
| Coos County | 87 | 187 |
| Crook County | 5 | 10 |
| Curry County | 54 | 119 |
| Deschutes County | 13 | 46 |
| Douglas County | 30 | 147 |
| Gilliam County | 10 | 68 |
| Grant County | 22 | 70 |
| Harney County | 45 | 347 |
| Hood River County | 1 | 3 |
| Jackson County | 17 | 75 |
| Jefferson County | 14 | 120 |
| Josephine County | 2 | 7 |
| Klamath County | 23 | 98 |
| Lake County | 73 | 539 |
| Lane County | 68 | 181 |
| Lincoln County | 49 | 113 |
| Linn County | 19 | 47 |
| Malheur County | 12 | 106 |
| Marion County | 13 | 86 |
| Multnomah County | 29 | 100 |