| San Marcos to Castle Pines (Colorado) | 811.58 mi (1,306.11 km) |
| San Marcos to Castle Rock (Colorado) | 809.53 mi (1,302.81 km) |
| San Marcos to Castro Valley (California) | 418.93 mi (674.21 km) |
| San Marcos to Catalina Foothills (Arizona) | 370.08 mi (595.59 km) |
| San Marcos to Cataño (Puerto Rico) | 3,298.58 mi (5,308.55 km) |
| San Marcos to Cathedral City (California) | 63.42 mi (102.06 km) |
| San Marcos to Catonsville (Maryland) | 2,274.43 mi (3,660.34 km) |
| San Marcos to Cave Spring (Virginia) | 2,104.34 mi (3,386.60 km) |
| San Marcos to Cayce (South Carolina) | 2,070.68 mi (3,332.44 km) |
| San Marcos to Cayey (Puerto Rico) | 3,308.13 mi (5,323.91 km) |
| San Marcos to Cedar City (Utah) | 389.15 mi (626.28 km) |
| San Marcos to Cedar Falls (Iowa) | 1,489.42 mi (2,396.98 km) |
| San Marcos to Cedar Hill (Texas) | 1,172.09 mi (1,886.30 km) |
| San Marcos to Cedar Lake (Indiana) | 1,721.38 mi (2,770.29 km) |
| San Marcos to Cedar Mill (Oregon) | 907.41 mi (1,460.34 km) |
