| Keystone to Cordele (Georgia) | 273.38 mi (439.97 km) |
| Keystone to Corinth (Mississippi) | 585.46 mi (942.21 km) |
| Keystone to Corinth (Texas) | 926.14 mi (1,490.48 km) |
| Keystone to Cornelius (North Carolina) | 517.14 mi (832.26 km) |
| Keystone to Cornelius (Oregon) | 2,503.58 mi (4,029.13 km) |
| Keystone to Corning (New York) | 1,017.18 mi (1,637.00 km) |
| Keystone to Corona (California) | 2,098.00 mi (3,376.40 km) |
| Keystone to Coronado (California) | 2,074.12 mi (3,337.97 km) |
| Keystone to Corpus Christi (Texas) | 901.95 mi (1,451.55 km) |
| Keystone to Corsicana (Texas) | 871.84 mi (1,403.09 km) |
| Keystone to Cortland (New York) | 1,062.34 mi (1,709.66 km) |
| Keystone to Corvallis (Oregon) | 2,498.69 mi (4,021.26 km) |
| Keystone to Coshocton (Ohio) | 839.23 mi (1,350.62 km) |
| Keystone to Costa Mesa (California) | 2,117.78 mi (3,408.24 km) |
| Keystone to Coto de Caza (California) | 2,098.88 mi (3,377.82 km) |
