| Gretna to Mauldin (South Carolina) | 563.49 mi (906.84 km) |
| Gretna to Maumee (Ohio) | 880.99 mi (1,417.81 km) |
| Gretna to Maumelle (Arkansas) | 367.90 mi (592.08 km) |
| Gretna to Mayagüez (Puerto Rico) | 1,651.63 mi (2,658.05 km) |
| Gretna to Mayfield Heights (Ohio) | 934.70 mi (1,504.25 km) |
| Gretna to Mays Chapel (Maryland) | 1,004.34 mi (1,616.33 km) |
| Gretna to Maywood (California) | 1,668.03 mi (2,684.44 km) |
| Gretna to Maywood (Illinois) | 836.12 mi (1,345.60 km) |
| Gretna to McAlester (Oklahoma) | 480.92 mi (773.97 km) |
| Gretna to McAllen (Texas) | 560.54 mi (902.11 km) |
| Gretna to McCalla (Alabama) | 294.14 mi (473.38 km) |
| Gretna to McComb (Mississippi) | 95.50 mi (153.70 km) |
| Gretna to McDonough (Georgia) | 423.98 mi (682.34 km) |
| Gretna to McFarland (California) | 1,734.69 mi (2,791.71 km) |
| Gretna to McHenry (Illinois) | 864.26 mi (1,390.90 km) |
