| Rockville to Delaware (Ohio) | 325.41 mi (523.70 km) |
| Rockville to Delhi (California) | 2,346.52 mi (3,776.36 km) |
| Rockville to Delray Beach (Florida) | 888.90 mi (1,430.54 km) |
| Rockville to Deltona (Florida) | 740.46 mi (1,191.65 km) |
| Rockville to Deming (New Mexico) | 1,771.53 mi (2,851.00 km) |
| Rockville to Denison (Texas) | 1,138.00 mi (1,831.44 km) |
| Rockville to Dent (Ohio) | 402.15 mi (647.19 km) |
| Rockville to Denton (Texas) | 1,183.38 mi (1,904.46 km) |
| Rockville to Dentsville (South Carolina) | 405.08 mi (651.91 km) |
| Rockville to Denver (Colorado) | 1,474.36 mi (2,372.75 km) |
| Rockville to Depew (New York) | 276.56 mi (445.08 km) |
| Rockville to Derby (Connecticut) | 264.89 mi (426.29 km) |
| Rockville to Derby (Kansas) | 1,092.41 mi (1,758.06 km) |
| Rockville to Des Moines (Iowa) | 882.21 mi (1,419.78 km) |
| Rockville to Des Moines (Washington) | 2,309.86 mi (3,717.35 km) |
