| Keystone to Castle Pines (Colorado) | 1,493.03 mi (2,402.80 km) |
| Keystone to Castle Rock (Colorado) | 1,489.71 mi (2,397.45 km) |
| Keystone to Castro Valley (California) | 2,363.43 mi (3,803.57 km) |
| Keystone to Catalina Foothills (Arizona) | 1,708.02 mi (2,748.79 km) |
| Keystone to Cataño (Puerto Rico) | 1,238.59 mi (1,993.32 km) |
| Keystone to Cathedral City (California) | 2,034.81 mi (3,274.71 km) |
| Keystone to Catonsville (Maryland) | 839.19 mi (1,350.55 km) |
| Keystone to Cave Spring (Virginia) | 646.10 mi (1,039.80 km) |
| Keystone to Cayce (South Carolina) | 412.18 mi (663.33 km) |
| Keystone to Cayey (Puerto Rico) | 1,250.73 mi (2,012.86 km) |
| Keystone to Cedar City (Utah) | 1,877.83 mi (3,022.07 km) |
| Keystone to Cedar Falls (Iowa) | 1,136.89 mi (1,829.65 km) |
| Keystone to Cedar Hill (Texas) | 908.69 mi (1,462.39 km) |
| Keystone to Cedar Lake (Indiana) | 954.61 mi (1,536.29 km) |
| Keystone to Cedar Mill (Oregon) | 2,492.15 mi (4,010.73 km) |
