| Gretna to Manassas (Virginia) | 940.20 mi (1,513.11 km) |
| Gretna to Manassas Park (Virginia) | 942.92 mi (1,517.48 km) |
| Gretna to Manatí (Puerto Rico) | 1,679.14 mi (2,702.32 km) |
| Gretna to Manchester (Missouri) | 599.80 mi (965.28 km) |
| Gretna to Manchester (New Hampshire) | 1,367.45 mi (2,200.70 km) |
| Gretna to Manchester (Tennessee) | 447.78 mi (720.64 km) |
| Gretna to Manchester (Virginia) | 888.35 mi (1,429.66 km) |
| Gretna to Mandan (North Dakota) | 1,305.15 mi (2,100.43 km) |
| Gretna to Mandeville (Louisiana) | 32.21 mi (51.84 km) |
| Gretna to Mango (Florida) | 486.51 mi (782.96 km) |
| Gretna to Manhattan (Kansas) | 741.13 mi (1,192.74 km) |
| Gretna to Manhattan (New York) | 1,173.95 mi (1,889.30 km) |
| Gretna to Manhattan Beach (California) | 1,679.80 mi (2,703.37 km) |
| Gretna to Manitowoc (Wisconsin) | 988.93 mi (1,591.53 km) |
| Gretna to Mankato (Minnesota) | 1,008.54 mi (1,623.09 km) |
