| Harker Heights to Oak Harbor (Washington) | 1,769.75 mi (2,848.15 km) |
| Harker Heights to Oak Hills (Oregon) | 1,681.58 mi (2,706.25 km) |
| Harker Heights to Oak Lawn (Illinois) | 917.78 mi (1,477.02 km) |
| Harker Heights to Oak Park (California) | 1,245.70 mi (2,004.76 km) |
| Harker Heights to Oak Park (Illinois) | 925.80 mi (1,489.92 km) |
| Harker Heights to Oak Park (Michigan) | 1,120.36 mi (1,803.04 km) |
| Harker Heights to Oak Ridge (Florida) | 988.59 mi (1,590.99 km) |
| Harker Heights to Oak Ridge (New Jersey) | 1,458.89 mi (2,347.85 km) |
| Harker Heights to Oak Ridge (Tennessee) | 839.54 mi (1,351.11 km) |
| Harker Heights to Oakdale (California) | 1,396.91 mi (2,248.10 km) |
| Harker Heights to Oakdale (Minnesota) | 995.18 mi (1,601.58 km) |
| Harker Heights to Oakland (California) | 1,470.55 mi (2,366.62 km) |
| Harker Heights to Oakland (New Jersey) | 1,471.37 mi (2,367.93 km) |
| Harker Heights to Oakland Park (Florida) | 1,111.71 mi (1,789.12 km) |
| Harker Heights to Oakleaf Plantation (Florida) | 941.38 mi (1,515.00 km) |
