| Rockville to Candler-McAfee (Georgia) | 541.52 mi (871.49 km) |
| Rockville to Caño Martin Peña (Puerto Rico) | 1,574.45 mi (2,533.83 km) |
| Rockville to Cañon City (Colorado) | 1,506.62 mi (2,424.67 km) |
| Rockville to Canóvanas (Puerto Rico) | 1,582.18 mi (2,546.27 km) |
| Rockville to Canton (Georgia) | 525.90 mi (846.36 km) |
| Rockville to Canton (Illinois) | 690.74 mi (1,111.63 km) |
| Rockville to Canton (Mississippi) | 847.82 mi (1,364.43 km) |
| Rockville to Canton (Ohio) | 252.90 mi (407.01 km) |
| Rockville to Canyon (Texas) | 1,390.17 mi (2,237.26 km) |
| Rockville to Canyon Lake (California) | 2,243.33 mi (3,610.29 km) |
| Rockville to Canyon Lake (Texas) | 1,355.33 mi (2,181.19 km) |
| Rockville to Cape Coral (Florida) | 903.81 mi (1,454.54 km) |
| Rockville to Cape Girardeau (Missouri) | 684.03 mi (1,100.83 km) |
| Rockville to Carbondale (Illinois) | 659.68 mi (1,061.66 km) |
| Rockville to Carlisle (Pennsylvania) | 77.19 mi (124.23 km) |
