| Hard to Carson (California) | 5,959.57 mi (9,590.99 km) |
| Hard to Carson City (Nevada) | 5,692.17 mi (9,160.66 km) |
| Hard to Carteret (New Jersey) | 3,988.62 mi (6,419.06 km) |
| Hard to Cartersville (Georgia) | 4,717.22 mi (7,591.63 km) |
| Hard to Carthage (Missouri) | 4,950.79 mi (7,967.53 km) |
| Hard to Cary (Illinois) | 4,475.61 mi (7,202.80 km) |
| Hard to Cary (North Carolina) | 4,391.52 mi (7,067.47 km) |
| Hard to Casa de Oro-Mount Helix (California) | 5,982.03 mi (9,627.14 km) |
| Hard to Casa Grande (Arizona) | 5,804.12 mi (9,340.82 km) |
| Hard to Casas Adobes (Arizona) | 5,810.41 mi (9,350.95 km) |
| Hard to Cascades (Virginia) | 4,186.05 mi (6,736.79 km) |
| Hard to Casper (Wyoming) | 5,078.57 mi (8,173.16 km) |
| Hard to Casselberry (Florida) | 4,831.97 mi (7,776.30 km) |
| Hard to Castaic (California) | 5,933.33 mi (9,548.77 km) |
| Hard to Castle Pines (Colorado) | 5,211.27 mi (8,386.73 km) |
