| Clarksburg to Oberkirch | 4,074.61 mi (6,557.45 km) |
| Clarksburg to Obernburg am Main | 4,078.59 mi (6,563.85 km) |
| Clarksburg to Obernkirchen | 4,006.96 mi (6,448.58 km) |
| Clarksburg to Oberschleissheim | 4,226.10 mi (6,801.25 km) |
| Clarksburg to Oberstdorf | 4,200.20 mi (6,759.57 km) |
| Clarksburg to Obertraubling | 4,227.23 mi (6,803.07 km) |
| Clarksburg to Obertshausen | 4,059.49 mi (6,533.11 km) |
| Clarksburg to Oberursel | 4,045.19 mi (6,510.11 km) |
| Clarksburg to Ochsenfurt | 4,121.48 mi (6,632.88 km) |
| Clarksburg to Ochsenhausen | 4,165.55 mi (6,703.80 km) |
| Clarksburg to Ochtrup | 3,933.95 mi (6,331.07 km) |
| Clarksburg to Odenthal | 3,963.21 mi (6,378.17 km) |
| Clarksburg to Oelde | 3,981.62 mi (6,407.80 km) |
| Clarksburg to Oelsnitz | 4,180.94 mi (6,728.57 km) |
| Clarksburg to Oer-Erkenschwick | 3,951.68 mi (6,359.62 km) |
