| Rio Grande City to Mankato (Minnesota) | 1,258.62 mi (2,025.55 km) |
| Rio Grande City to Manor (Texas) | 285.79 mi (459.93 km) |
| Rio Grande City to Manorville (New York) | 1,789.86 mi (2,880.51 km) |
| Rio Grande City to Mansfield (Ohio) | 1,362.01 mi (2,191.94 km) |
| Rio Grande City to Mansfield (Texas) | 439.60 mi (707.47 km) |
| Rio Grande City to Manteca (California) | 1,524.21 mi (2,452.97 km) |
| Rio Grande City to Manville (New Jersey) | 1,695.98 mi (2,729.42 km) |
| Rio Grande City to Maple Grove (Minnesota) | 1,327.64 mi (2,136.63 km) |
| Rio Grande City to Maple Heights (Ohio) | 1,429.12 mi (2,299.95 km) |
| Rio Grande City to Maple Valley (Washington) | 1,921.12 mi (3,091.74 km) |
| Rio Grande City to Mapleton (Utah) | 1,198.88 mi (1,929.41 km) |
| Rio Grande City to Maplewood (Minnesota) | 1,324.99 mi (2,132.37 km) |
| Rio Grande City to Marana (Arizona) | 851.27 mi (1,369.98 km) |
| Rio Grande City to Marco Island (Florida) | 1,061.55 mi (1,708.40 km) |
| Rio Grande City to Margate (Florida) | 1,151.60 mi (1,853.32 km) |
