| Boulder to Carlsbad (New Mexico) | 529.76 mi (852.57 km) |
| Boulder to Carmel (Indiana) | 1,009.41 mi (1,624.49 km) |
| Boulder to Carmichael (California) | 863.26 mi (1,389.28 km) |
| Boulder to Carney (Maryland) | 1,520.87 mi (2,447.60 km) |
| Boulder to Carnot-Moon (Pennsylvania) | 1,315.75 mi (2,117.50 km) |
| Boulder to Carol Stream (Illinois) | 901.18 mi (1,450.31 km) |
| Boulder to Carolina (Puerto Rico) | 2,766.83 mi (4,452.79 km) |
| Boulder to Carolina Forest (South Carolina) | 1,511.97 mi (2,433.27 km) |
| Boulder to Carpentersville (Illinois) | 893.81 mi (1,438.45 km) |
| Boulder to Carpinteria (California) | 874.30 mi (1,407.06 km) |
| Boulder to Carrboro (North Carolina) | 1,447.41 mi (2,329.38 km) |
| Boulder to Carroll (Iowa) | 559.03 mi (899.66 km) |
| Boulder to Carrollton (Georgia) | 1,197.91 mi (1,927.85 km) |
| Boulder to Carrollton (Texas) | 671.30 mi (1,080.35 km) |
| Boulder to Carrollwood (Florida) | 1,535.14 mi (2,470.57 km) |
