| Merthyr Tudful to River Ridge (Louisiana) | 4,495.12 mi (7,234.20 km) |
| Merthyr Tudful to Riverbank (California) | 5,202.37 mi (8,372.41 km) |
| Merthyr Tudful to Riverdale (Georgia) | 4,078.72 mi (6,564.06 km) |
| Merthyr Tudful to Riverdale (Illinois) | 3,826.62 mi (6,158.35 km) |
| Merthyr Tudful to Riverside (California) | 5,302.44 mi (8,533.45 km) |
| Merthyr Tudful to Riverside (Ohio) | 3,773.85 mi (6,073.42 km) |
| Merthyr Tudful to Riverton (Utah) | 4,759.96 mi (7,660.41 km) |
| Merthyr Tudful to Riverton (Wyoming) | 4,508.81 mi (7,256.22 km) |
| Merthyr Tudful to Riverview (Florida) | 4,273.79 mi (6,877.99 km) |
| Merthyr Tudful to Riverview (Michigan) | 3,629.63 mi (5,841.32 km) |
| Merthyr Tudful to Riviera Beach (Florida) | 4,231.82 mi (6,810.46 km) |
| Merthyr Tudful to Riviera Beach (Maryland) | 3,494.34 mi (5,623.60 km) |
| Merthyr Tudful to Roanoke (Virginia) | 3,720.39 mi (5,987.39 km) |
| Merthyr Tudful to Roanoke Rapids (North Carolina) | 3,663.50 mi (5,895.83 km) |
| Merthyr Tudful to Robbinsdale (Minnesota) | 3,885.19 mi (6,252.61 km) |
