| Wheat Ridge to Oberkirch | 5,099.03 mi (8,206.09 km) |
| Wheat Ridge to Obernburg am Main | 5,072.71 mi (8,163.74 km) |
| Wheat Ridge to Obernkirchen | 4,958.20 mi (7,979.45 km) |
| Wheat Ridge to Oberschleissheim | 5,228.02 mi (8,413.68 km) |
| Wheat Ridge to Oberstdorf | 5,226.16 mi (8,410.69 km) |
| Wheat Ridge to Obertraubling | 5,212.45 mi (8,388.63 km) |
| Wheat Ridge to Obertshausen | 5,052.01 mi (8,130.43 km) |
| Wheat Ridge to Oberursel | 5,037.27 mi (8,106.70 km) |
| Wheat Ridge to Ochsenfurt | 5,111.77 mi (8,226.60 km) |
| Wheat Ridge to Ochsenhausen | 5,183.28 mi (8,341.68 km) |
| Wheat Ridge to Ochtrup | 4,900.22 mi (7,886.14 km) |
| Wheat Ridge to Odenthal | 4,951.33 mi (7,968.39 km) |
| Wheat Ridge to Oelde | 4,947.81 mi (7,962.74 km) |
| Wheat Ridge to Oelsnitz | 5,141.60 mi (8,274.61 km) |
| Wheat Ridge to Oer-Erkenschwick | 4,927.84 mi (7,930.59 km) |
