| Helena to Castle Pines (Colorado) | 610.47 mi (982.45 km) |
| Helena to Castle Rock (Colorado) | 615.93 mi (991.24 km) |
| Helena to Castro Valley (California) | 799.73 mi (1,287.03 km) |
| Helena to Catalina Foothills (Arizona) | 989.30 mi (1,592.13 km) |
| Helena to Cataño (Puerto Rico) | 3,238.64 mi (5,212.08 km) |
| Helena to Cathedral City (California) | 911.90 mi (1,467.56 km) |
| Helena to Catonsville (Maryland) | 1,838.11 mi (2,958.16 km) |
| Helena to Cave Spring (Virginia) | 1,753.91 mi (2,822.64 km) |
| Helena to Cayce (South Carolina) | 1,835.51 mi (2,953.97 km) |
| Helena to Cayey (Puerto Rico) | 3,254.25 mi (5,237.20 km) |
| Helena to Cedar City (Utah) | 618.28 mi (995.02 km) |
| Helena to Cedar Falls (Iowa) | 1,000.65 mi (1,610.40 km) |
| Helena to Cedar Hill (Texas) | 1,252.81 mi (2,016.20 km) |
| Helena to Cedar Lake (Indiana) | 1,268.41 mi (2,041.30 km) |
| Helena to Cedar Mill (Oregon) | 521.55 mi (839.36 km) |
