| Boulder to Coldwater (Michigan) | 1,062.14 mi (1,709.36 km) |
| Boulder to Colesville (Maryland) | 1,500.26 mi (2,414.44 km) |
| Boulder to College (Alaska) | 2,400.31 mi (3,862.92 km) |
| Boulder to College Park (Georgia) | 1,227.86 mi (1,976.05 km) |
| Boulder to College Park (Maryland) | 1,504.87 mi (2,421.86 km) |
| Boulder to College Station (Texas) | 823.90 mi (1,325.94 km) |
| Boulder to Collegedale (Tennessee) | 1,156.01 mi (1,860.42 km) |
| Boulder to Colleyville (Texas) | 667.02 mi (1,073.47 km) |
| Boulder to Collierville (Tennessee) | 917.37 mi (1,476.36 km) |
| Boulder to Collinsville (Illinois) | 818.86 mi (1,317.83 km) |
| Boulder to Colonia (New Jersey) | 1,622.09 mi (2,610.51 km) |
| Boulder to Colonial Heights (Virginia) | 1,509.01 mi (2,428.52 km) |
| Boulder to Colonial Park (Pennsylvania) | 1,495.62 mi (2,406.97 km) |
| Boulder to Colorado Springs (Colorado) | 84.16 mi (135.45 km) |
| Boulder to Colton (California) | 782.23 mi (1,258.87 km) |
