| Difficult Run to Darby (Pennsylvania) | 131.76 mi (212.05 km) |
| Difficult Run to Dardenne Prairie (Missouri) | 719.86 mi (1,158.50 km) |
| Difficult Run to Darien (Illinois) | 593.18 mi (954.63 km) |
| Difficult Run to Davenport (Iowa) | 722.21 mi (1,162.29 km) |
| Difficult Run to Davidson (North Carolina) | 303.91 mi (489.10 km) |
| Difficult Run to Davie (Florida) | 902.23 mi (1,451.99 km) |
| Difficult Run to Davis (California) | 2,368.54 mi (3,811.80 km) |
| Difficult Run to Dayton (Nevada) | 2,243.50 mi (3,610.56 km) |
| Difficult Run to Dayton (Ohio) | 371.11 mi (597.24 km) |
| Difficult Run to Daytona Beach (Florida) | 703.72 mi (1,132.52 km) |
| Difficult Run to De Pere (Wisconsin) | 671.98 mi (1,081.44 km) |
| Difficult Run to De Witt (New York) | 292.77 mi (471.17 km) |
| Difficult Run to Dearborn (Michigan) | 387.43 mi (623.50 km) |
| Difficult Run to Dearborn Heights (Michigan) | 390.24 mi (628.02 km) |
| Difficult Run to DeBary (Florida) | 728.71 mi (1,172.74 km) |
