| Rockville to Cordele (Georgia) | 616.71 mi (992.51 km) |
| Rockville to Corinth (Mississippi) | 688.07 mi (1,107.35 km) |
| Rockville to Corinth (Texas) | 1,181.78 mi (1,901.89 km) |
| Rockville to Cornelius (North Carolina) | 322.75 mi (519.42 km) |
| Rockville to Cornelius (Oregon) | 2,354.11 mi (3,788.57 km) |
| Rockville to Corning (New York) | 211.74 mi (340.76 km) |
| Rockville to Corona (California) | 2,255.22 mi (3,629.42 km) |
| Rockville to Coronado (California) | 2,264.46 mi (3,644.29 km) |
| Rockville to Corpus Christi (Texas) | 1,400.58 mi (2,254.02 km) |
| Rockville to Corsicana (Texas) | 1,184.90 mi (1,906.91 km) |
| Rockville to Cortland (New York) | 248.30 mi (399.60 km) |
| Rockville to Corvallis (Oregon) | 2,372.57 mi (3,818.28 km) |
| Rockville to Coshocton (Ohio) | 262.47 mi (422.41 km) |
| Rockville to Costa Mesa (California) | 2,278.76 mi (3,667.31 km) |
| Rockville to Coto de Caza (California) | 2,263.01 mi (3,641.97 km) |
