| Rio Grande City to Merriam (Kansas) | 905.28 mi (1,456.91 km) |
| Rio Grande City to Merrick (New York) | 1,747.80 mi (2,812.81 km) |
| Rio Grande City to Merrifield (Virginia) | 1,517.33 mi (2,441.90 km) |
| Rio Grande City to Merrillville (Indiana) | 1,231.16 mi (1,981.36 km) |
| Rio Grande City to Merritt Island (Florida) | 1,120.83 mi (1,803.81 km) |
| Rio Grande City to Mesa (Arizona) | 911.03 mi (1,466.15 km) |
| Rio Grande City to Mesquite (Nevada) | 1,150.87 mi (1,852.14 km) |
| Rio Grande City to Mesquite (Texas) | 460.74 mi (741.49 km) |
| Rio Grande City to Metairie (Louisiana) | 582.44 mi (937.34 km) |
| Rio Grande City to Methuen Town (Massachusetts) | 1,921.56 mi (3,092.46 km) |
| Rio Grande City to Metuchen (New Jersey) | 1,706.53 mi (2,746.40 km) |
| Rio Grande City to Mexico (Missouri) | 970.25 mi (1,561.46 km) |
| Rio Grande City to Miami (Florida) | 1,154.71 mi (1,858.32 km) |
| Rio Grande City to Miami (Oklahoma) | 762.04 mi (1,226.38 km) |
| Rio Grande City to Miami Beach (Florida) | 1,158.82 mi (1,864.95 km) |
