| Potomac to Carrollwood (Florida) | 816.26 mi (1,313.64 km) |
| Potomac to Carson (California) | 2,291.04 mi (3,687.08 km) |
| Potomac to Carson City (Nevada) | 2,260.78 mi (3,638.37 km) |
| Potomac to Carteret (New Jersey) | 191.21 mi (307.72 km) |
| Potomac to Cartersville (Georgia) | 538.50 mi (866.63 km) |
| Potomac to Carthage (Missouri) | 938.95 mi (1,511.09 km) |
| Potomac to Cary (Illinois) | 619.95 mi (997.71 km) |
| Potomac to Cary (North Carolina) | 240.47 mi (387.00 km) |
| Potomac to Casa de Oro-Mount Helix (California) | 2,249.56 mi (3,620.32 km) |
| Potomac to Casa Grande (Arizona) | 1,966.33 mi (3,164.50 km) |
| Potomac to Casas Adobes (Arizona) | 1,941.17 mi (3,124.01 km) |
| Potomac to Cascades (Virginia) | 10.60 mi (17.06 km) |
| Potomac to Casper (Wyoming) | 1,535.37 mi (2,470.95 km) |
| Potomac to Casselberry (Florida) | 753.19 mi (1,212.15 km) |
| Potomac to Castaic (California) | 2,295.46 mi (3,694.18 km) |
