| San Marcos to Mattoon (Illinois) | 1,655.13 mi (2,663.68 km) |
| San Marcos to Mauldin (South Carolina) | 1,991.65 mi (3,205.26 km) |
| San Marcos to Maumee (Ohio) | 1,916.80 mi (3,084.80 km) |
| San Marcos to Maumelle (Arkansas) | 1,420.54 mi (2,286.14 km) |
| San Marcos to Mayagüez (Puerto Rico) | 3,249.04 mi (5,228.82 km) |
| San Marcos to Mayfield Heights (Ohio) | 2,030.16 mi (3,267.22 km) |
| San Marcos to Mays Chapel (Maryland) | 2,278.87 mi (3,667.49 km) |
| San Marcos to Maywood (California) | 82.96 mi (133.51 km) |
| San Marcos to Maywood (Illinois) | 1,707.12 mi (2,747.35 km) |
| San Marcos to McAlester (Oklahoma) | 1,229.30 mi (1,978.36 km) |
| San Marcos to McAllen (Texas) | 1,229.99 mi (1,979.48 km) |
| San Marcos to McCalla (Alabama) | 1,736.30 mi (2,794.30 km) |
| San Marcos to McComb (Mississippi) | 1,562.63 mi (2,514.81 km) |
| San Marcos to McDonough (Georgia) | 1,899.34 mi (3,056.69 km) |
| San Marcos to McFarland (California) | 211.55 mi (340.45 km) |
