| Rockville to Clarksdale (Mississippi) | 815.75 mi (1,312.82 km) |
| Rockville to Clarkston (Georgia) | 536.07 mi (862.72 km) |
| Rockville to Clarksville (Indiana) | 467.15 mi (751.81 km) |
| Rockville to Clarksville (Tennessee) | 582.03 mi (936.68 km) |
| Rockville to Clawson (Michigan) | 393.81 mi (633.78 km) |
| Rockville to Clay (Alabama) | 643.69 mi (1,035.91 km) |
| Rockville to Clayton (California) | 2,397.17 mi (3,857.86 km) |
| Rockville to Clayton (Missouri) | 708.83 mi (1,140.74 km) |
| Rockville to Clayton (North Carolina) | 247.04 mi (397.57 km) |
| Rockville to Clayton (Ohio) | 386.32 mi (621.73 km) |
| Rockville to Clearfield (Utah) | 1,835.99 mi (2,954.75 km) |
| Rockville to Clearlake (California) | 2,414.92 mi (3,886.44 km) |
| Rockville to Clearwater (Florida) | 831.96 mi (1,338.91 km) |
| Rockville to Cleburne (Texas) | 1,224.41 mi (1,970.50 km) |
| Rockville to Clemmons (North Carolina) | 275.22 mi (442.92 km) |
