| Difficult Run to Clarksdale (Mississippi) | 801.76 mi (1,290.31 km) |
| Difficult Run to Clarkston (Georgia) | 520.08 mi (836.99 km) |
| Difficult Run to Clarksville (Indiana) | 456.19 mi (734.17 km) |
| Difficult Run to Clarksville (Tennessee) | 569.04 mi (915.77 km) |
| Difficult Run to Clawson (Michigan) | 394.09 mi (634.22 km) |
| Difficult Run to Clay (Alabama) | 628.27 mi (1,011.11 km) |
| Difficult Run to Clayton (California) | 2,389.88 mi (3,846.14 km) |
| Difficult Run to Clayton (Missouri) | 699.01 mi (1,124.94 km) |
| Difficult Run to Clayton (North Carolina) | 232.09 mi (373.52 km) |
| Difficult Run to Clayton (Ohio) | 378.70 mi (609.45 km) |
| Difficult Run to Clearfield (Utah) | 1,829.50 mi (2,944.30 km) |
| Difficult Run to Clearlake (California) | 2,408.14 mi (3,875.53 km) |
| Difficult Run to Clearwater (Florida) | 816.28 mi (1,313.68 km) |
| Difficult Run to Cleburne (Texas) | 1,211.06 mi (1,949.02 km) |
| Difficult Run to Clemmons (North Carolina) | 258.98 mi (416.79 km) |
