| Duncan to Oak Harbor (Washington) | 1,582.76 mi (2,547.21 km) |
| Duncan to Oak Hills (Oregon) | 1,512.32 mi (2,433.84 km) |
| Duncan to Oak Lawn (Illinois) | 741.38 mi (1,193.14 km) |
| Duncan to Oak Park (California) | 1,187.06 mi (1,910.39 km) |
| Duncan to Oak Park (Illinois) | 747.44 mi (1,202.89 km) |
| Duncan to Oak Park (Michigan) | 964.67 mi (1,552.49 km) |
| Duncan to Oak Ridge (Florida) | 1,057.05 mi (1,701.17 km) |
| Duncan to Oak Ridge (New Jersey) | 1,350.43 mi (2,173.31 km) |
| Duncan to Oak Ridge (Tennessee) | 774.52 mi (1,246.48 km) |
| Duncan to Oakdale (California) | 1,294.84 mi (2,083.84 km) |
| Duncan to Oakdale (Minnesota) | 767.93 mi (1,235.86 km) |
| Duncan to Oakland (California) | 1,369.66 mi (2,204.26 km) |
| Duncan to Oakland (New Jersey) | 1,363.50 mi (2,194.34 km) |
| Duncan to Oakland Park (Florida) | 1,204.04 mi (1,937.72 km) |
| Duncan to Oakleaf Plantation (Florida) | 985.06 mi (1,585.29 km) |
