| Potomac to Ridgeland (Mississippi) | 856.23 mi (1,377.97 km) |
| Potomac to Ridgewood (New Jersey) | 212.33 mi (341.71 km) |
| Potomac to Rifle (Colorado) | 1,628.01 mi (2,620.03 km) |
| Potomac to Rincon (Georgia) | 516.58 mi (831.35 km) |
| Potomac to Ringwood (New Jersey) | 211.48 mi (340.35 km) |
| Potomac to Río Grande (Puerto Rico) | 1,579.96 mi (2,542.70 km) |
| Potomac to Rio Grande City (Texas) | 1,524.24 mi (2,453.03 km) |
| Potomac to Rio Linda (California) | 2,356.92 mi (3,793.09 km) |
| Potomac to Rio Rancho (New Mexico) | 1,637.74 mi (2,635.68 km) |
| Potomac to Rio Rico (Arizona) | 1,963.79 mi (3,160.42 km) |
| Potomac to Ripon (California) | 2,358.07 mi (3,794.94 km) |
| Potomac to River Edge (New Jersey) | 213.02 mi (342.82 km) |
| Potomac to River Falls (Wisconsin) | 888.02 mi (1,429.14 km) |
| Potomac to River Forest (Illinois) | 592.52 mi (953.57 km) |
| Potomac to River Grove (Illinois) | 594.00 mi (955.95 km) |
