| River Grove to Oberkirch | 4,371.27 mi (7,034.89 km) |
| River Grove to Obernburg am Main | 4,360.28 mi (7,017.19 km) |
| River Grove to Obernkirchen | 4,266.72 mi (6,866.63 km) |
| River Grove to Oberschleissheim | 4,513.30 mi (7,263.46 km) |
| River Grove to Oberstdorf | 4,498.99 mi (7,240.43 km) |
| River Grove to Obertraubling | 4,506.26 mi (7,252.13 km) |
| River Grove to Obertshausen | 4,340.17 mi (6,984.83 km) |
| River Grove to Oberursel | 4,325.48 mi (6,961.19 km) |
| River Grove to Ochsenfurt | 4,401.78 mi (7,083.98 km) |
| River Grove to Ochsenhausen | 4,459.89 mi (7,177.50 km) |
| River Grove to Ochtrup | 4,200.16 mi (6,759.50 km) |
| River Grove to Odenthal | 4,240.57 mi (6,824.53 km) |
| River Grove to Oelde | 4,248.39 mi (6,837.13 km) |
| River Grove to Oelsnitz | 4,447.45 mi (7,157.48 km) |
| River Grove to Oer-Erkenschwick | 4,222.99 mi (6,796.25 km) |
