| Potomac to Cloverleaf (Texas) | 1,203.56 mi (1,936.94 km) |
| Potomac to Cloverly (Maryland) | 12.24 mi (19.70 km) |
| Potomac to Clovis (California) | 2,299.72 mi (3,701.04 km) |
| Potomac to Clovis (New Mexico) | 1,468.68 mi (2,363.61 km) |
| Potomac to Clute (Texas) | 1,246.43 mi (2,005.94 km) |
| Potomac to Coachella (California) | 2,181.46 mi (3,510.72 km) |
| Potomac to Coalinga (California) | 2,347.98 mi (3,778.70 km) |
| Potomac to Coamo (Puerto Rico) | 1,586.02 mi (2,552.45 km) |
| Potomac to Coatesville (Pennsylvania) | 99.33 mi (159.86 km) |
| Potomac to Cockeysville (Maryland) | 44.18 mi (71.10 km) |
| Potomac to Cocoa (Florida) | 762.59 mi (1,227.28 km) |
| Potomac to Cocoa Beach (Florida) | 763.78 mi (1,229.19 km) |
| Potomac to Coconut Creek (Florida) | 896.69 mi (1,443.09 km) |
| Potomac to Coeur d'Alene (Idaho) | 2,052.89 mi (3,303.80 km) |
| Potomac to Cohoes (New York) | 317.14 mi (510.39 km) |
