| The Dalles to Oskaloosa (Iowa) | 1,454.19 mi (2,340.30 km) |
| The Dalles to Oswego (Illinois) | 1,652.47 mi (2,659.40 km) |
| The Dalles to Oswego (New York) | 2,177.26 mi (3,503.96 km) |
| The Dalles to Otsego (Minnesota) | 1,329.88 mi (2,140.23 km) |
| The Dalles to Ottawa (Illinois) | 1,636.96 mi (2,634.42 km) |
| The Dalles to Ottawa (Kansas) | 1,406.56 mi (2,263.64 km) |
| The Dalles to Ottumwa (Iowa) | 1,471.90 mi (2,368.79 km) |
| The Dalles to Overland (Missouri) | 1,637.47 mi (2,635.26 km) |
| The Dalles to Overland Park (Kansas) | 1,424.65 mi (2,292.76 km) |
| The Dalles to Overlea (Maryland) | 2,285.76 mi (3,678.58 km) |
| The Dalles to Oviedo (Florida) | 2,460.50 mi (3,959.79 km) |
| The Dalles to Owasso (Oklahoma) | 1,462.81 mi (2,354.16 km) |
| The Dalles to Owatonna (Minnesota) | 1,366.21 mi (2,198.69 km) |
| The Dalles to Owensboro (Kentucky) | 1,823.95 mi (2,935.36 km) |
| The Dalles to Owings Mills (Maryland) | 2,271.17 mi (3,655.10 km) |
