| Keystone to Cadillac (Michigan) | 1,124.48 mi (1,809.68 km) |
| Keystone to Caguas (Puerto Rico) | 1,252.51 mi (2,015.72 km) |
| Keystone to Cahokia (Illinois) | 842.48 mi (1,355.84 km) |
| Keystone to Calabasas (California) | 2,161.61 mi (3,478.78 km) |
| Keystone to Caldwell (Idaho) | 2,165.39 mi (3,484.86 km) |
| Keystone to Caledonia (Wisconsin) | 1,055.43 mi (1,698.56 km) |
| Keystone to Calera (Alabama) | 423.93 mi (682.25 km) |
| Keystone to Calexico (California) | 1,977.22 mi (3,182.03 km) |
| Keystone to Calhoun (Georgia) | 460.55 mi (741.18 km) |
| Keystone to California (Maryland) | 785.56 mi (1,264.23 km) |
| Keystone to California City (California) | 2,119.02 mi (3,410.23 km) |
| Keystone to Callaway (Florida) | 225.84 mi (363.46 km) |
| Keystone to Calumet City (Illinois) | 972.41 mi (1,564.95 km) |
| Keystone to Calverton (Maryland) | 821.56 mi (1,322.18 km) |
| Keystone to Camano (Washington) | 2,529.87 mi (4,071.43 km) |
