Region
- North CarolinaBladen County3
- North CarolinaRobeson County3
- Northern Cheyenne Indian Reservation (Mont.)3
- OklahomaWichita Mountains Wildlife Refuge3
- Southern States3
- Wichita Mountains Wildlife Refuge (Okla.)3
- Asia2
- Black Creek Aquifer (S.C. and N.C.)2
- High Plains Aquifer2
- NevadaNevada National Security Site2
- TexasGalveston2
- TexasHouston2
- Washington (D.C.)2
- Western Sahara2
- Africa1
- American River Watershed (Calif.)1
- Atlantic States1
- Baton Rouge Region (La.)1
- Burke County (Ga.)1
- Campbell County (Tenn.)1