| Keystone to Marysville (California) | 2,347.46 mi (3,777.88 km) |
| Keystone to Marysville (Ohio) | 836.92 mi (1,346.89 km) |
| Keystone to Marysville (Washington) | 2,513.79 mi (4,045.55 km) |
| Keystone to Maryville (Missouri) | 1,094.57 mi (1,761.54 km) |
| Keystone to Maryville (Tennessee) | 532.34 mi (856.72 km) |
| Keystone to Mason (Ohio) | 781.73 mi (1,258.07 km) |
| Keystone to Mason City (Iowa) | 1,193.89 mi (1,921.38 km) |
| Keystone to Massapequa (New York) | 1,009.14 mi (1,624.05 km) |
| Keystone to Massapequa Park (New York) | 1,010.56 mi (1,626.34 km) |
| Keystone to Massillon (Ohio) | 876.33 mi (1,410.32 km) |
| Keystone to Mastic (New York) | 1,035.69 mi (1,666.78 km) |
| Keystone to Mastic Beach (New York) | 1,033.58 mi (1,663.39 km) |
| Keystone to Matteson (Illinois) | 968.86 mi (1,559.22 km) |
| Keystone to Matthews (North Carolina) | 495.45 mi (797.34 km) |
| Keystone to Mattoon (Illinois) | 850.38 mi (1,368.56 km) |
