| Keystone to Clarksdale (Mississippi) | 630.01 mi (1,013.91 km) |
| Keystone to Clarkston (Georgia) | 404.32 mi (650.68 km) |
| Keystone to Clarksville (Indiana) | 727.38 mi (1,170.61 km) |
| Keystone to Clarksville (Tennessee) | 645.12 mi (1,038.21 km) |
| Keystone to Clawson (Michigan) | 995.80 mi (1,602.59 km) |
| Keystone to Clay (Alabama) | 451.85 mi (727.18 km) |
| Keystone to Clayton (California) | 2,357.52 mi (3,794.06 km) |
| Keystone to Clayton (Missouri) | 851.56 mi (1,370.45 km) |
| Keystone to Clayton (North Carolina) | 574.11 mi (923.94 km) |
| Keystone to Clayton (Ohio) | 816.97 mi (1,314.79 km) |
| Keystone to Clearfield (Utah) | 1,884.98 mi (3,033.58 km) |
| Keystone to Clearlake (California) | 2,401.95 mi (3,865.56 km) |
| Keystone to Clearwater (Florida) | 14.44 mi (23.25 km) |
| Keystone to Cleburne (Texas) | 930.27 mi (1,497.13 km) |
| Keystone to Clemmons (North Carolina) | 561.01 mi (902.85 km) |
