Specimen ID | State | County | Locality | Year |
| Drainage name | Status |
280419
| MD | Montgomery | Potomac River, side channels on N side of Swainsons Island, ca. 0.5 miles downstream (E of) I-495 crossing, SW side of Bethesda | 2010 |
02070008
| Middle Potomac-Catoctin | established |
280416
| 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 | 2010 |
02070008
| Middle Potomac-Catoctin | established |