Locations
| Name | Sites | Samples |
|---|---|---|
| Hudspeth County | 14 | 82 |
| Hughes County | 1 | 2 |
| Humphreys County | 3 | 31 |
| Hungary | 52 | 94 |
| Hyde County | 1 | 5 |
| Independence County | 1 | 4 |
| Indiana County | 8 | 73 |
| Ionia County | 2 | 14 |
| Iran | 3 | 3 |
| Ireland | 454 | 1879 |
| Iron County | 1 | 1 |
| Isle of Wight County | 2 | 6 |
| Issaquena County | 4 | 20 |
| Italy | 190 | 611 |
| Itasca County | 6 | 19 |
| Itawamba County | 8 | 49 |
| Jackson County | 2 | 8 |
| Jackson County | 1 | 1 |
| Jackson County | 2 | 2 |
| Jackson County | 1 | 5 |
| Jackson County | 5 | 30 |
| Jackson County | 4 | 6 |
| Jackson County | 7 | 18 |
| Jackson County | 4 | 27 |
| James City County | 11 | 30 |
| Jasper County | 1 | 1 |
| Jasper County | 1 | 3 |
| Jasper County | 4 | 13 |
| Jasper County | 1 | 3 |
| Jeff Davis County | 7 | 10 |