| River Grove to Oerlinghausen | 4,261.93 mi (6,858.91 km) |
| River Grove to Oestrich-Winkel | 4,311.91 mi (6,939.35 km) |
| River Grove to Offenburg | 4,368.16 mi (7,029.87 km) |
| River Grove to Oftersheim | 4,357.78 mi (7,013.16 km) |
| River Grove to Ohrdruf | 4,379.69 mi (7,048.43 km) |
| River Grove to Ohringen | 4,398.50 mi (7,078.71 km) |
| River Grove to Olbernhau | 4,478.78 mi (7,207.91 km) |
| River Grove to Olching | 4,506.03 mi (7,251.76 km) |
| River Grove to Oldenburg | 4,202.21 mi (6,762.80 km) |
| River Grove to Oldenburg in Holstein | 4,251.03 mi (6,841.38 km) |
| River Grove to Olfen | 4,225.05 mi (6,799.56 km) |
| River Grove to Olpe | 4,267.42 mi (6,867.75 km) |
| River Grove to Olsberg | 4,278.53 mi (6,885.62 km) |
| River Grove to Oranienburg | 4,391.05 mi (7,066.71 km) |
| River Grove to Ortenberg | 4,337.20 mi (6,980.05 km) |
