| Abbreviation | Definition |
|---|---|
| MHCO | Marquette and Huron Mountain Railroad |
| MHFU | MHF Services |
| MHFX | MHF Logistical Solutions |
| MHFX | MHF Logistical Solutions Incorporated |
| MHLX | General American Transportation Corporation (GATX) |
| MHM | Mt. Hope Mineral Railroad (Norfolk Southern) |
| MHO | Maryn Rail Yard Hump Oil |
| MHQU | Military Sealift Command |
| MHQU | U.S. Department of Defense - Military Sealift Command HQ Washington DC |
| MHQZ | Military Sealift Command |
| MHQZ | U.S. Department of Defense - Military Sealift Command |
| MHRX | Mile-High Railcar Services |
| MHRX | Mile-High Railcar Services Incorporated |
| MHWA | Mohawk Adirondack and Northern Railroad Corporation |
| MHWA | Mohawk, Adirondack and Northern Railroad |
| MI | Missouri-Illinois Railroad (Union Pacific Railroad) |
| MI | Union Pacific Railroad Company |
| MIA | Miami Amtrak Station |
| MID | Midway Railroad |
| MIDH | Middletown and Hummelstown Railroad |