| Rio Grande City to Mount Washington (Kentucky) | 1,115.98 mi (1,795.99 km) |
| Rio Grande City to Mountain Brook (Alabama) | 873.24 mi (1,405.35 km) |
| Rio Grande City to Mountain Home (Arkansas) | 785.17 mi (1,263.61 km) |
| Rio Grande City to Mountain Home (Idaho) | 1,496.35 mi (2,408.14 km) |
| Rio Grande City to Mountain House (California) | 1,539.33 mi (2,477.31 km) |
| Rio Grande City to Mountain Park (Georgia) | 1,016.69 mi (1,636.20 km) |
| Rio Grande City to Mountain Top (Pennsylvania) | 1,656.05 mi (2,665.16 km) |
| Rio Grande City to Mountain View (California) | 1,556.16 mi (2,504.41 km) |
| Rio Grande City to Mountlake Terrace (Washington) | 1,949.94 mi (3,138.12 km) |
| Rio Grande City to Mukilteo (Washington) | 1,955.12 mi (3,146.47 km) |
| Rio Grande City to Muncie (Indiana) | 1,226.91 mi (1,974.52 km) |
| Rio Grande City to Mundelein (Illinois) | 1,256.77 mi (2,022.58 km) |
| Rio Grande City to Munhall (Pennsylvania) | 1,453.23 mi (2,338.74 km) |
| Rio Grande City to Munster (Indiana) | 1,229.80 mi (1,979.17 km) |
| Rio Grande City to Murfreesboro (Tennessee) | 981.66 mi (1,579.83 km) |
