| San Marcos to Smyrna (Delaware) | 2,334.95 mi (3,757.73 km) |
| San Marcos to Smyrna (Georgia) | 1,874.33 mi (3,016.44 km) |
| San Marcos to Smyrna (Tennessee) | 1,747.81 mi (2,812.83 km) |
| San Marcos to Snellville (Georgia) | 1,903.56 mi (3,063.48 km) |
| San Marcos to Snoqualmie (Washington) | 1,023.98 mi (1,647.93 km) |
| San Marcos to Snyder (Texas) | 942.68 mi (1,517.10 km) |
| San Marcos to Socastee (South Carolina) | 2,188.81 mi (3,522.55 km) |
| San Marcos to Socorro (Texas) | 644.83 mi (1,037.75 km) |
| San Marcos to Soddy-Daisy (Tennessee) | 1,826.75 mi (2,939.87 km) |
| San Marcos to Solana Beach (California) | 10.85 mi (17.46 km) |
| San Marcos to Soledad (California) | 328.85 mi (529.24 km) |
| San Marcos to Solon (Ohio) | 2,030.11 mi (3,267.14 km) |
| San Marcos to Somers Point (New Jersey) | 2,388.35 mi (3,843.67 km) |
| San Marcos to Somerset (Kentucky) | 1,851.49 mi (2,979.69 km) |
| San Marcos to Somerset (New Jersey) | 2,390.47 mi (3,847.09 km) |
