| South Portland to Hutchinson (Kansas) | 1,486.16 mi (2,391.74 km) |
| South Portland to Hutchinson (Minnesota) | 1,190.71 mi (1,916.26 km) |
| South Portland to Hutto (Texas) | 1,741.39 mi (2,802.49 km) |
| South Portland to Hyattsville (Maryland) | 472.80 mi (760.89 km) |
| South Portland to Hybla Valley (Virginia) | 488.09 mi (785.51 km) |
| South Portland to Idaho Falls (Idaho) | 2,067.75 mi (3,327.72 km) |
| South Portland to Idylwood (Virginia) | 485.84 mi (781.89 km) |
| South Portland to Ilchester (Maryland) | 453.17 mi (729.31 km) |
| South Portland to Immokalee (Florida) | 1,342.52 mi (2,160.57 km) |
| South Portland to Imperial (California) | 2,533.78 mi (4,077.72 km) |
| South Portland to Imperial Beach (California) | 2,620.58 mi (4,217.42 km) |
| South Portland to Independence (Kentucky) | 806.43 mi (1,297.83 km) |
| South Portland to Independence (Missouri) | 1,281.71 mi (2,062.71 km) |
| South Portland to Indian Trail (North Carolina) | 808.68 mi (1,301.45 km) |
| South Portland to Indiana (Pennsylvania) | 499.28 mi (803.51 km) |
