| Boulder to Cloverly (Maryland) | 1,499.88 mi (2,413.82 km) |
| Boulder to Clovis (California) | 810.68 mi (1,304.67 km) |
| Boulder to Clovis (New Mexico) | 402.29 mi (647.43 km) |
| Boulder to Clute (Texas) | 943.22 mi (1,517.97 km) |
| Boulder to Coachella (California) | 743.40 mi (1,196.39 km) |
| Boulder to Coalinga (California) | 861.17 mi (1,385.92 km) |
| Boulder to Coamo (Puerto Rico) | 2,762.90 mi (4,446.45 km) |
| Boulder to Coatesville (Pennsylvania) | 1,550.53 mi (2,495.33 km) |
| Boulder to Cockeysville (Maryland) | 1,514.34 mi (2,437.10 km) |
| Boulder to Cocoa (Florida) | 1,605.95 mi (2,584.53 km) |
| Boulder to Cocoa Beach (Florida) | 1,614.83 mi (2,598.82 km) |
| Boulder to Coconut Creek (Florida) | 1,723.76 mi (2,774.13 km) |
| Boulder to Coeur d'Alene (Idaho) | 780.80 mi (1,256.58 km) |
| Boulder to Cohoes (New York) | 1,636.27 mi (2,633.33 km) |
| Boulder to Cold Springs (Nevada) | 780.44 mi (1,255.99 km) |
