| Keystone to McKeesport (Pennsylvania) | 858.10 mi (1,380.98 km) |
| Keystone to McKinleyville (California) | 2,494.36 mi (4,014.28 km) |
| Keystone to McKinney (Texas) | 905.43 mi (1,457.15 km) |
| Keystone to McLean (Virginia) | 808.91 mi (1,301.81 km) |
| Keystone to McMinnville (Oregon) | 2,504.97 mi (4,031.35 km) |
| Keystone to McMinnville (Tennessee) | 554.26 mi (891.99 km) |
| Keystone to McNair (Virginia) | 804.70 mi (1,295.04 km) |
| Keystone to McPherson (Kansas) | 1,118.90 mi (1,800.69 km) |
| Keystone to Mead Valley (California) | 2,081.90 mi (3,350.50 km) |
| Keystone to Meadow Woods (Florida) | 78.03 mi (125.58 km) |
| Keystone to Meadowbrook (Virginia) | 707.82 mi (1,139.12 km) |
| Keystone to Meadville (Pennsylvania) | 944.07 mi (1,519.33 km) |
| Keystone to Mebane (North Carolina) | 582.91 mi (938.11 km) |
| Keystone to Mechanicsville (Virginia) | 722.83 mi (1,163.29 km) |
| Keystone to Medford (Massachusetts) | 1,178.70 mi (1,896.93 km) |
