| Merthyr Tudful to Marshall (Minnesota) | 4,001.05 mi (6,439.06 km) |
| Merthyr Tudful to Marshall (Missouri) | 4,159.88 mi (6,694.67 km) |
| Merthyr Tudful to Marshall (Texas) | 4,530.94 mi (7,291.84 km) |
| Merthyr Tudful to Marshalltown (Iowa) | 4,009.09 mi (6,452.00 km) |
| Merthyr Tudful to Marshfield (Wisconsin) | 3,785.52 mi (6,092.21 km) |
| Merthyr Tudful to Martha Lake (Washington) | 4,668.37 mi (7,513.02 km) |
| Merthyr Tudful to Martin (Tennessee) | 4,124.25 mi (6,637.33 km) |
| Merthyr Tudful to Martinez (California) | 5,222.91 mi (8,405.46 km) |
| Merthyr Tudful to Martinez (Georgia) | 3,985.47 mi (6,414.00 km) |
| Merthyr Tudful to Martinsburg (West Virginia) | 3,540.69 mi (5,698.20 km) |
| Merthyr Tudful to Martinsville (Indiana) | 3,882.41 mi (6,248.14 km) |
| Merthyr Tudful to Martinsville (New Jersey) | 3,351.29 mi (5,393.38 km) |
| Merthyr Tudful to Martinsville (Virginia) | 3,744.01 mi (6,025.41 km) |
| Merthyr Tudful to Maryland City (Maryland) | 3,508.52 mi (5,646.41 km) |
| Merthyr Tudful to Maryland Heights (Missouri) | 4,073.74 mi (6,556.05 km) |
