| Keystone to Clemson (South Carolina) | 452.91 mi (728.88 km) |
| Keystone to Clermont (Florida) | 60.23 mi (96.92 km) |
| Keystone to Cleveland (Mississippi) | 618.03 mi (994.63 km) |
| Keystone to Cleveland (Ohio) | 923.52 mi (1,486.26 km) |
| Keystone to Cleveland (Tennessee) | 505.07 mi (812.83 km) |
| Keystone to Cleveland Heights (Ohio) | 926.32 mi (1,490.77 km) |
| Keystone to Cliffside Park (New Jersey) | 1,003.48 mi (1,614.94 km) |
| Keystone to Clifton (Colorado) | 1,661.09 mi (2,673.27 km) |
| Keystone to Clifton (New Jersey) | 1,001.26 mi (1,611.36 km) |
| Keystone to Clinton (Iowa) | 1,040.39 mi (1,674.35 km) |
| Keystone to Clinton (Maryland) | 803.31 mi (1,292.80 km) |
| Keystone to Clinton (Mississippi) | 546.18 mi (879.00 km) |
| Keystone to Clinton (Utah) | 1,887.86 mi (3,038.21 km) |
| Keystone to Clive (Iowa) | 1,125.10 mi (1,810.67 km) |
| Keystone to Cloquet (Minnesota) | 1,391.81 mi (2,239.90 km) |
