Specimen ID | State | County | Locality | Year |
| Drainage name | Status |
280485
| MD | Montgomery | Potomac River, upstream and downstream ends of Plummers Island and Swainson Island area, just E of I-495 crossing, W side of Bethesda | 1995 |
02070008
| Middle Potomac-Catoctin | established |
280486
| VA | Fairfax | Little Difficult Run by Stuart Mill Road, ca. 1.4 road miles E off Fox Mill Road, 4.1 air miles WNW center of Vienna | 2010 |
02070008
| Middle Potomac-Catoctin | established |
746352
| VA | Fairfax | Little Difficult Run by Stuart Mill Road, ca. 1.4 road miles E off Fox Mill Road, 4.1 air miles WNW center of Vienna | 2010 |
02070008
| Middle Potomac-Catoctin | established |