| Rio Grande City to Oerlinghausen | 5,485.36 mi (8,827.83 km) |
| Rio Grande City to Oestrich-Winkel | 5,527.11 mi (8,895.03 km) |
| Rio Grande City to Offenburg | 5,576.73 mi (8,974.89 km) |
| Rio Grande City to Oftersheim | 5,571.37 mi (8,966.25 km) |
| Rio Grande City to Ohrdruf | 5,602.00 mi (9,015.55 km) |
| Rio Grande City to Ohringen | 5,612.93 mi (9,033.14 km) |
| Rio Grande City to Olbernhau | 5,704.10 mi (9,179.86 km) |
| Rio Grande City to Olching | 5,719.62 mi (9,204.83 km) |
| Rio Grande City to Oldenburg | 5,428.90 mi (8,736.98 km) |
| Rio Grande City to Oldenburg in Holstein | 5,483.51 mi (8,824.85 km) |
| Rio Grande City to Olfen | 5,445.94 mi (8,764.39 km) |
| Rio Grande City to Olpe | 5,486.34 mi (8,829.41 km) |
| Rio Grande City to Olsberg | 5,499.57 mi (8,850.70 km) |
| Rio Grande City to Oranienburg | 5,621.99 mi (9,047.72 km) |
| Rio Grande City to Ortenberg | 5,555.42 mi (8,940.58 km) |
