| Rio Grande City to Mendota (California) | 1,452.40 mi (2,337.42 km) |
| Rio Grande City to Mendota Heights (Minnesota) | 1,316.62 mi (2,118.90 km) |
| Rio Grande City to Menifee (California) | 1,206.53 mi (1,941.72 km) |
| Rio Grande City to Menlo Park (California) | 1,562.42 mi (2,514.47 km) |
| Rio Grande City to Menomonee Falls (Wisconsin) | 1,305.45 mi (2,100.91 km) |
| Rio Grande City to Menomonie (Wisconsin) | 1,335.16 mi (2,148.73 km) |
| Rio Grande City to Mentor (Ohio) | 1,450.67 mi (2,334.63 km) |
| Rio Grande City to Mequon (Wisconsin) | 1,314.17 mi (2,114.95 km) |
| Rio Grande City to Merced (California) | 1,472.92 mi (2,370.44 km) |
| Rio Grande City to Mercedes (Texas) | 58.45 mi (94.07 km) |
| Rio Grande City to Mercer Island (Washington) | 1,937.06 mi (3,117.39 km) |
| Rio Grande City to Mercerville (New Jersey) | 1,681.43 mi (2,706.01 km) |
| Rio Grande City to Meriden (Connecticut) | 1,810.66 mi (2,913.97 km) |
| Rio Grande City to Meridian (Idaho) | 1,544.65 mi (2,485.87 km) |
| Rio Grande City to Meridian (Mississippi) | 737.07 mi (1,186.20 km) |
