| San Marcos to McHenry (Illinois) | 1,691.08 mi (2,721.53 km) |
| San Marcos to McKeesport (Pennsylvania) | 2,109.48 mi (3,394.87 km) |
| San Marcos to McKinleyville (California) | 660.37 mi (1,062.76 km) |
| San Marcos to McKinney (Texas) | 1,184.15 mi (1,905.71 km) |
| San Marcos to McLean (Virginia) | 2,251.07 mi (3,622.75 km) |
| San Marcos to McMinnville (Oregon) | 893.80 mi (1,438.43 km) |
| San Marcos to McMinnville (Tennessee) | 1,790.54 mi (2,881.59 km) |
| San Marcos to McNair (Virginia) | 2,239.39 mi (3,603.95 km) |
| San Marcos to McPherson (Kansas) | 1,149.79 mi (1,850.41 km) |
| San Marcos to Mead Valley (California) | 48.67 mi (78.33 km) |
| San Marcos to Meadow Woods (Florida) | 2,142.22 mi (3,447.57 km) |
| San Marcos to Meadowbrook (Virginia) | 2,242.16 mi (3,608.41 km) |
| San Marcos to Meadville (Pennsylvania) | 2,098.18 mi (3,376.69 km) |
| San Marcos to Mebane (North Carolina) | 2,151.33 mi (3,462.23 km) |
| San Marcos to Mechanicsville (Virginia) | 2,247.56 mi (3,617.10 km) |
