| San Marcos to Maryland Heights (Missouri) | 1,536.78 mi (2,473.22 km) |
| San Marcos to Marysville (California) | 482.90 mi (777.15 km) |
| San Marcos to Marysville (Ohio) | 1,924.03 mi (3,096.43 km) |
| San Marcos to Marysville (Washington) | 1,064.62 mi (1,713.34 km) |
| San Marcos to Maryville (Missouri) | 1,326.96 mi (2,135.53 km) |
| San Marcos to Maryville (Tennessee) | 1,891.12 mi (3,043.47 km) |
| San Marcos to Mason (Ohio) | 1,870.46 mi (3,010.21 km) |
| San Marcos to Mason City (Iowa) | 1,467.69 mi (2,362.02 km) |
| San Marcos to Massapequa (New York) | 2,444.16 mi (3,933.50 km) |
| San Marcos to Massapequa Park (New York) | 2,445.23 mi (3,935.22 km) |
| San Marcos to Massillon (Ohio) | 2,022.70 mi (3,255.22 km) |
| San Marcos to Mastic (New York) | 2,476.39 mi (3,985.36 km) |
| San Marcos to Mastic Beach (New York) | 2,477.08 mi (3,986.47 km) |
| San Marcos to Matteson (Illinois) | 1,707.33 mi (2,747.69 km) |
| San Marcos to Matthews (North Carolina) | 2,078.47 mi (3,344.98 km) |
