| River Ridge to Oerlinghausen | 4,966.97 mi (7,993.56 km) |
| River Ridge to Oestrich-Winkel | 5,000.04 mi (8,046.79 km) |
| River Ridge to Offenburg | 5,043.89 mi (8,117.36 km) |
| River Ridge to Oftersheim | 5,042.67 mi (8,115.40 km) |
| River Ridge to Ohrdruf | 5,081.84 mi (8,178.44 km) |
| River Ridge to Ohringen | 5,084.81 mi (8,183.22 km) |
| River Ridge to Olbernhau | 5,187.13 mi (8,347.87 km) |
| River Ridge to Olching | 5,190.33 mi (8,353.03 km) |
| River Ridge to Oldenburg | 4,914.86 mi (7,909.71 km) |
| River Ridge to Oldenburg in Holstein | 4,978.21 mi (8,011.65 km) |
| River Ridge to Olfen | 4,924.85 mi (7,925.78 km) |
| River Ridge to Olpe | 4,963.01 mi (7,987.19 km) |
| River Ridge to Olsberg | 4,978.42 mi (8,012.00 km) |
| River Ridge to Oranienburg | 5,113.44 mi (8,229.29 km) |
| River Ridge to Ortenberg | 5,031.10 mi (8,096.77 km) |
