| The Dalles to Olympia (Washington) | 128.60 mi (206.96 km) |
| The Dalles to Olympia Heights (Florida) | 2,632.47 mi (4,236.55 km) |
| The Dalles to Omaha (Nebraska) | 1,290.23 mi (2,076.43 km) |
| The Dalles to On Top of the World Designated Place (Florida) | 2,389.46 mi (3,845.46 km) |
| The Dalles to Onalaska (Wisconsin) | 1,467.06 mi (2,361.01 km) |
| The Dalles to Oneida (New York) | 2,225.77 mi (3,582.04 km) |
| The Dalles to Oneonta (New York) | 2,269.42 mi (3,652.28 km) |
| The Dalles to Ontario (California) | 821.11 mi (1,321.46 km) |
| The Dalles to Ontario (Oregon) | 233.20 mi (375.30 km) |
| The Dalles to Opa-locka (Florida) | 2,628.21 mi (4,229.69 km) |
| The Dalles to Opelika (Alabama) | 2,094.43 mi (3,370.65 km) |
| The Dalles to Opelousas (Louisiana) | 1,878.68 mi (3,023.44 km) |
| The Dalles to Orange (California) | 834.53 mi (1,343.04 km) |
| The Dalles to Orange (Texas) | 1,823.96 mi (2,935.38 km) |
| The Dalles to Orange City (Florida) | 2,443.66 mi (3,932.69 km) |
