| Harpenden to Clarkston (Georgia) | 4,181.64 mi (6,729.70 km) |
| Harpenden to Clarksville (Indiana) | 4,024.84 mi (6,477.36 km) |
| Harpenden to Clarksville (Tennessee) | 4,171.15 mi (6,712.81 km) |
| Harpenden to Clawson (Michigan) | 3,727.44 mi (5,998.74 km) |
| Harpenden to Clay (Alabama) | 4,282.96 mi (6,892.75 km) |
| Harpenden to Clayton (California) | 5,307.78 mi (8,542.05 km) |
| Harpenden to Clayton (Missouri) | 4,186.34 mi (6,737.27 km) |
| Harpenden to Clayton (North Carolina) | 3,856.65 mi (6,206.67 km) |
| Harpenden to Clayton (Ohio) | 3,895.56 mi (6,269.29 km) |
| Harpenden to Clearfield (Utah) | 4,825.05 mi (7,765.17 km) |
| Harpenden to Clearlake (California) | 5,269.05 mi (8,479.71 km) |
| Harpenden to Clearwater (Florida) | 4,410.92 mi (7,098.69 km) |
| Harpenden to Cleburne (Texas) | 4,775.45 mi (7,685.34 km) |
| Harpenden to Clemmons (North Carolina) | 3,918.18 mi (6,305.70 km) |
| Harpenden to Clemson (South Carolina) | 4,081.31 mi (6,568.23 km) |
