| South Portland to Grand Junction (Colorado) | 1,991.75 mi (3,205.41 km) |
| South Portland to Grand Prairie (Texas) | 1,627.18 mi (2,618.69 km) |
| South Portland to Grand Rapids (Michigan) | 773.02 mi (1,244.06 km) |
| South Portland to Grand Rapids (Minnesota) | 1,149.56 mi (1,850.04 km) |
| South Portland to Grand Terrace (California) | 2,579.84 mi (4,151.85 km) |
| South Portland to Grandview (Missouri) | 1,295.69 mi (2,085.21 km) |
| South Portland to Grandview (Washington) | 2,393.75 mi (3,852.36 km) |
| South Portland to Grandville (Michigan) | 778.68 mi (1,253.17 km) |
| South Portland to Granger (Indiana) | 814.06 mi (1,310.11 km) |
| South Portland to Granite Bay (California) | 2,625.10 mi (4,224.69 km) |
| South Portland to Granite City (Illinois) | 1,082.63 mi (1,742.33 km) |
| South Portland to Grants Pass (Oregon) | 2,633.62 mi (4,238.40 km) |
| South Portland to Grantsville (Utah) | 2,148.71 mi (3,458.02 km) |
| South Portland to Grapevine (Texas) | 1,619.87 mi (2,606.93 km) |
| South Portland to Grass Valley (California) | 2,606.27 mi (4,194.38 km) |
