| Highlands Ranch to Nuth | 4,924.29 mi (7,924.87 km) |
| Highlands Ranch to Oegstgeest | 4,821.50 mi (7,759.45 km) |
| Highlands Ranch to Oirschot | 4,878.99 mi (7,851.98 km) |
| Highlands Ranch to Oisterwijk | 4,872.00 mi (7,840.73 km) |
| Highlands Ranch to Oldebroek | 4,856.37 mi (7,815.58 km) |
| Highlands Ranch to Oldenzaal | 4,895.52 mi (7,878.58 km) |
| Highlands Ranch to Ommen | 4,870.00 mi (7,837.51 km) |
| Highlands Ranch to Oosterend | 4,837.10 mi (7,784.56 km) |
| Highlands Ranch to Oosterhout | 4,858.04 mi (7,818.26 km) |
| Highlands Ranch to Oosterwolde | 4,844.85 mi (7,797.03 km) |
| Highlands Ranch to Oostzaan | 4,824.18 mi (7,763.76 km) |
| Highlands Ranch to Opmeer | 4,814.65 mi (7,748.43 km) |
| Highlands Ranch to Oss | 4,874.28 mi (7,844.40 km) |
| Highlands Ranch to Oud-Beijerland | 4,835.32 mi (7,781.70 km) |
| Highlands Ranch to Oudenbosch | 4,849.39 mi (7,804.33 km) |
