| Rockville to Cibolo (Texas) | 1,364.95 mi (2,196.67 km) |
| Rockville to Cicero (Illinois) | 588.68 mi (947.40 km) |
| Rockville to Cimarron Hills (Colorado) | 1,473.97 mi (2,372.12 km) |
| Rockville to Cincinnati (Ohio) | 393.99 mi (634.06 km) |
| Rockville to Cinco Ranch (Texas) | 1,237.89 mi (1,992.19 km) |
| Rockville to Circleville (Ohio) | 310.79 mi (500.17 km) |
| Rockville to Citrus (California) | 2,266.28 mi (3,647.23 km) |
| Rockville to Citrus Heights (California) | 2,349.67 mi (3,781.43 km) |
| Rockville to Citrus Park (Florida) | 821.53 mi (1,322.12 km) |
| Rockville to Claiborne (Louisiana) | 954.77 mi (1,536.55 km) |
| Rockville to Claremont (California) | 2,256.74 mi (3,631.88 km) |
| Rockville to Claremont (New Hampshire) | 388.16 mi (624.68 km) |
| Rockville to Claremore (Oklahoma) | 1,024.97 mi (1,649.53 km) |
| Rockville to Clarksburg (Maryland) | 11.41 mi (18.37 km) |
| Rockville to Clarksburg (West Virginia) | 170.23 mi (273.95 km) |
