| Duncan to Hazleton (Pennsylvania) | 1,274.09 mi (2,050.45 km) |
| Duncan to Healdsburg (California) | 1,407.76 mi (2,265.58 km) |
| Duncan to Heath (Ohio) | 929.86 mi (1,496.46 km) |
| Duncan to Heber (Utah) | 844.41 mi (1,358.95 km) |
| Duncan to Helena (Alabama) | 638.77 mi (1,028.00 km) |
| Duncan to Helena (Montana) | 1,110.74 mi (1,787.56 km) |
| Duncan to Hemet (California) | 1,090.69 mi (1,755.30 km) |
| Duncan to Henderson (Kentucky) | 619.64 mi (997.22 km) |
| Duncan to Henderson (Nevada) | 969.55 mi (1,560.35 km) |
| Duncan to Henderson (North Carolina) | 1,103.15 mi (1,775.35 km) |
| Duncan to Henderson (Texas) | 244.22 mi (393.03 km) |
| Duncan to Hendersonville (North Carolina) | 876.73 mi (1,410.96 km) |
| Duncan to Hendersonville (Tennessee) | 648.62 mi (1,043.85 km) |
| Duncan to Hercules (California) | 1,372.43 mi (2,208.71 km) |
| Duncan to Hereford (Texas) | 255.18 mi (410.68 km) |
