| San Marcos to Carrollwood (Florida) | 2,081.35 mi (3,349.61 km) |
| San Marcos to Carson (California) | 78.99 mi (127.13 km) |
| San Marcos to Carson City (Nevada) | 439.71 mi (707.65 km) |
| San Marcos to Carteret (New Jersey) | 2,404.63 mi (3,869.87 km) |
| San Marcos to Cartersville (Georgia) | 1,855.53 mi (2,986.19 km) |
| San Marcos to Carthage (Missouri) | 1,317.13 mi (2,119.72 km) |
| San Marcos to Cary (Illinois) | 1,691.40 mi (2,722.05 km) |
| San Marcos to Cary (North Carolina) | 2,178.84 mi (3,506.51 km) |
| San Marcos to Casa de Oro-Mount Helix (California) | 28.27 mi (45.49 km) |
| San Marcos to Casa Grande (Arizona) | 313.89 mi (505.15 km) |
| San Marcos to Casas Adobes (Arizona) | 362.29 mi (583.04 km) |
| San Marcos to Cascades (Virginia) | 2,240.44 mi (3,605.64 km) |
| San Marcos to Casper (Wyoming) | 892.40 mi (1,436.17 km) |
| San Marcos to Casselberry (Florida) | 2,137.53 mi (3,440.02 km) |
| San Marcos to Castaic (California) | 125.13 mi (201.38 km) |
