| Mason City to Dover (New Hampshire) | 1,121.18 mi (1,804.36 km) |
| Mason City to Dover (New Jersey) | 967.44 mi (1,556.94 km) |
| Mason City to Dover (Ohio) | 629.17 mi (1,012.55 km) |
| Mason City to Downers Grove (Illinois) | 280.14 mi (450.83 km) |
| Mason City to Downey (California) | 1,482.44 mi (2,385.76 km) |
| Mason City to Dranesville (Virginia) | 871.45 mi (1,402.46 km) |
| Mason City to Draper (Utah) | 976.01 mi (1,570.74 km) |
| Mason City to Drexel Heights (Arizona) | 1,233.02 mi (1,984.36 km) |
| Mason City to Drexel Hill (Pennsylvania) | 949.39 mi (1,527.90 km) |
| Mason City to Duarte (California) | 1,465.42 mi (2,358.37 km) |
| Mason City to Dublin (California) | 1,546.91 mi (2,489.51 km) |
| Mason City to Dublin (Georgia) | 921.38 mi (1,482.82 km) |
| Mason City to Dublin (Ohio) | 559.59 mi (900.57 km) |
| Mason City to Dubuque (Iowa) | 134.02 mi (215.69 km) |
| Mason City to Duluth (Georgia) | 797.76 mi (1,283.87 km) |
