| Napa to Oswego (Illinois) | 1,801.26 mi (2,898.85 km) |
| Napa to Oswego (New York) | 2,388.66 mi (3,844.18 km) |
| Napa to Otsego (Minnesota) | 1,544.61 mi (2,485.81 km) |
| Napa to Ottawa (Illinois) | 1,777.66 mi (2,860.87 km) |
| Napa to Ottawa (Kansas) | 1,457.87 mi (2,346.21 km) |
| Napa to Ottumwa (Iowa) | 1,592.75 mi (2,563.28 km) |
| Napa to Overland (Missouri) | 1,718.13 mi (2,765.07 km) |
| Napa to Overland Park (Kansas) | 1,486.11 mi (2,391.66 km) |
| Napa to Overlea (Maryland) | 2,438.53 mi (3,924.43 km) |
| Napa to Oviedo (Florida) | 2,439.53 mi (3,926.04 km) |
| Napa to Owasso (Oklahoma) | 1,456.60 mi (2,344.17 km) |
| Napa to Owatonna (Minnesota) | 1,554.54 mi (2,501.79 km) |
| Napa to Owensboro (Kentucky) | 1,903.58 mi (3,063.52 km) |
| Napa to Owings Mills (Maryland) | 2,423.55 mi (3,900.32 km) |
| Napa to Owosso (Michigan) | 2,007.26 mi (3,230.37 km) |
