| Wheat Ridge to Oerlinghausen | 4,957.99 mi (7,979.12 km) |
| Wheat Ridge to Oestrich-Winkel | 5,027.87 mi (8,091.57 km) |
| Wheat Ridge to Offenburg | 5,097.09 mi (8,202.97 km) |
| Wheat Ridge to Oftersheim | 5,076.52 mi (8,169.87 km) |
| Wheat Ridge to Ohrdruf | 5,076.78 mi (8,170.28 km) |
| Wheat Ridge to Ohringen | 5,114.70 mi (8,231.32 km) |
| Wheat Ridge to Olbernhau | 5,165.46 mi (8,313.00 km) |
| Wheat Ridge to Olching | 5,222.28 mi (8,404.45 km) |
| Wheat Ridge to Oldenburg | 4,889.50 mi (7,868.89 km) |
| Wheat Ridge to Oldenburg in Holstein | 4,916.32 mi (7,912.04 km) |
| Wheat Ridge to Olfen | 4,928.69 mi (7,931.96 km) |
| Wheat Ridge to Olpe | 4,975.35 mi (8,007.05 km) |
| Wheat Ridge to Olsberg | 4,980.81 mi (8,015.84 km) |
| Wheat Ridge to Oranienburg | 5,060.03 mi (8,143.34 km) |
| Wheat Ridge to Ortenberg | 5,045.64 mi (8,120.18 km) |
