List of reporting marks: M

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Note: Marks ending in U are for container owners; marks ending in X are not common carriers; marks ending in Z are for trailers without flanged wheels. All other marks are of common-carrier railroads.

M

• MAA - Magma Arizona Railroad
• MAAX - Maxx Leasing Company
• MACX - Mac Acquisitions
• MADU - Magnum Speditionsgelleshaft
• MAEU - Maersk Lines
• MAGX - Magnimet, Monroe Scrap Division
• MAIX - Macon Iron and Paper Stock
• MAJU - Malaysian International Shipping Corporation
• MALX - Mid-America Locomotive and Car Repair
• MALZ - American President Lines
• MANX - Manchester Gas Company; Williams Energy Ventures
• MAPX - MAPCO Products Company; Williams Energy Ventures
• MARX - MidAmerican Energy Corporation
• MARZ - MARTRAC
• MASX - GE Rail Services
• MATU - Matson Navigation Company
• MATX - Merchants Investment Company
• MATZ - Matson Navigation Company
• MAW - Maumee and Western Railroad
• MAXU - Maxu Containers
• MAXX - MidAmerican Energy Company
• MAYW - Maywood and Sugar Creek
• MB - Meridian & Bigbee Railroad
• MBBX - Tank Car Services
• MBCX - MBCX Leasing
• MBFX - MBF Industries
• MBIX - Morse Brothers
• MBKX - MRC Rail Services
• MBLX - Exxon-Mobil Corporation
• MBPX - MacMillan-Bloedell
• MBRR - Meridian & Bigbee Railroad
• MBSX - Mid-South Bulk Services
• MBT - Marianna and Blountstown Railroad
• MBTX - Massachusetts Bay Transportation Authority
• MC - Michigan Central Railroad; New York Central Railroad; Penn Central; Maine Coast Railroad (1991-2000); Massachusetts Coastal Railroad (2007-)
• MCCX - Mount Vernon Coal Transfer Company; Mount Vernon Transfer Terminal
• MCDX - Redland Worth Corporation; Sunbelt Cement
• MCER - Massachusetts Central Railroad
• MCEU - Massachusetts Central Railroad
• MCEZ - Massachusetts Central Railroad
• MCHX - Trinity Rail Management
• MCIX - Mobley Company (Applied Chemicals Division)
• MCLR - McLaughlin Line Railroad
• MCLX - Morrison Car Leasing
• MCMU - Management Control and Maintenance
• MCMX - MC Rail Services
• MCPX - Monsanto Company; Solutia
• MCR - McCloud River Railroad; McCloud Railway
• MCRR - Monongahela Connecting Railroad
• MCRX - Marcus Rail Transport
• MCRY - Mid Continent Railway
• MCSA - Moscow, Camden and San Augustine Railroad
• MCSU - China Ocean Shipping Company
• MCTA - Minnesota Central Railroad
• MCTX - Modern Continental Construction Company
• MCVX - Massachusetts Call Volunteer Firefighters' Association
• MD - Municipal Docks
• MDAX - Merchants Despatch Transportation Corporation
• MDCX - Mexicana De Cobre, SA de CV
• MDDE - Maryland and Delaware Railroad
• MDDX - Old Line Holding Company
• MDIX - Modern Dispersions
• MDKX - Gardau MRM Steel (Mandak Metal Processors Division)
• MDLR - Midland Terminal Company
• MDP - Mexican Pacific Railroad (Ferrocarril Mexicano del Pacifico)
• MDR - Kansas City Southern Railway
• MDS - Meridian Southern Railway
• MDSB - Burlington Northern Railroad
• MDSZ - Medspan Shipping Service
• MDT - Merchants Despatch Transportation Corporation
• MDTX - Merchants Despatch Refrigerator Line
• MDW - Minnesota, Dakota & Western Railway
• MDWU - Minnesota, Dakota & Western Railway
• MDWZ - Minnesota, Dakota & Western Railway
• ME - Morristown & Erie Railway
• MEC - Maine Central Railroad; Pan Am Railways
• MECX - Trinity Rail Management
• MEDU - Mediterranean Shipping Company
• MEFX - MexFresh
• MEFZ - MexFresh
• MELX - Sunbelt Cement
• MEPX - McGraw-Edison Company
• MERR - Maine Eastern Railroad
• MERX - Merco
• MESX - Mears/CPG
• MET - Modesto and Empire Traction Company
• METW - Municipality of East Troy Wisconsin
• METX - Northeast Illinois Regional Commuter Railroad Corporation (Metra)
• MF - Middle Fork Railroad
• MFCX - Farmers Coop Grain and Supply Company; First Union Rail
• MFFX - M4 Holdings
• MG - Mobile and Gulf Railroad
• MGA - Monongahela Railway; Norfolk Southern
• MGGU - Marcevaggi
• MGMX - J and J Partnership
• MGRI - MG Rail
• MGRS - Ferrocarriles Nacionales de Mexico
• MGRX - M&G Resins USA, LLC
• MGSX - Martin Gas Sales; CF Martin Sulphur
• MH - Mount Hood Railroad
• MHAX - United States Department of the Interior (Bureau of Mines Helium Field Operations)
• MHCO - Marquette and Huron Mountain Railroad
• MHFX - MHF Logistical Solutions
• MHLX - General American Transportation Corporation
• MHM - Norfolk Southern
• MHQU - Military Sealift Command (Washington, DC)
• MHQZ - Military Sealift Command
• MHRX - Mile-High Railcar Services
• MHWA - Mohawk, Adirondack and Northern Railroad
• MI - Missouri-Illinois Railroad; Missouri Pacific Railroad; Union Pacific
• MICO - Midland Continental Railroad
• MID - Midway Railroad
• MIDH - Middletown and Hummelstown Railroad
• MIDL - Midland Railway
• MIDX - MRC Rail Services
• MIEU - MI Engineering
• MIGN - Michigan Northern Railway
• MILW - Milwaukee Road; Soo Line Railroad; Canadian Pacific Railway
• MILX - Milchem; GE Rail Services Corporation
• MILZ - Soo Line Railroad, Canadian Pacific Railway
• MIMX - Minera Mexico International
• MINE - Minneapolis Eastern Railway
• MINU - China Ocean Shipping Company
• MIPX - Millennium Petrochemicals
• MIR - Minneapolis Industrial Railway
• MIRX - Regional Recycling
• MIS - Mississippi Central Railroad
• MISS - Mississippian Railway
• MISU - Malaysian International Shipping Corporation
• MISX - Milwaukee Solvents and Chemicals Corporation
• MJ - Manufacturers' Junction Railway
• MJRX - M Ryan Railway Service Contractors
• MJVU - Merco
• MKC - McKeesport Connecting Railroad
• MKCX - Morrison-Knudsen
• MKFX - Century Rail Enterprises
• MKIX - M-K Railroad Equipment Leasing Company; Morrison-Knudsen
• MKNR - Mackenzie Northern Railway
• MKT - Missouri-Kansas-Texas Railroad; Union Pacific
• MKTT - Missouri-Kansas-Texas Railroad; Union Pacific
• MKTZ - Union Pacific
• MLCU - NYK Line
• MLCX - American Refrigerator Transit Company
• MLD - Midland Railway Co. of Manitoba
• MLEX - Miles
• MLHX - American Refrigerator Transit Company
• MLIX - Melbo Land and Investment Company
• MLLX - Montell USA, Basell USA
• MLMX - Morrison Grain Company; Metal Management
• MLRX - Maddie’s Locomotive Leasing & Resale
• MLSX - Monsanto Company
• MLUX - Solutia
• MMA - Montreal, Maine & Atlantic Railway
• MMAC - Montreal, Maine & Atlantic Railway
• MMAX - Martin Marietta Aluminum; Martin Marietta Corporation
• MMBX - Martin Marietta Corporation; Master Builders
• MMCU - CIE Des Messageries Maritimes
• MMCX - M&M Chemical Products; TransMatrix
• MMID - Maryland Midland Railway
• MMMU - Fesco Pacific Lines
• MMMX - Minnesota Mining and Manufacturing (3M)
• MMRR - Mid-Michigan Railroad
• MMRX - Double M Ranch Enterprises
• MMSX - Blue Circle
• MMXZ - Murphy Motor Express
• MNA - Missouri & Northern Arkansas Railroad
• MNAX - C and S Directional Boring
• MNBR - Meridian & Bigbee Railroad
• MNC - Missouri North Central Railroad
• MNCW - Metro-North Commuter Railroad
• MNCX - Minnesota Corn Processors
• MNJ - Middletown and New Jersey Railway
• MNLU - Malaysian International Shipping Corporation
• MNLX - Exxon-Mobil Corporation
• MNN - Minnesota Northern Railroad
• MNNR - Minnesota Commercial Railway
• MNPX - Morton Norwich Products; Morton International
• MNRX - Northstar Line
• MNS - Minneapolis, Northfield and Southern Railway; Soo Line Railroad; Canadian Pacific Railway
• MNTX - Minnesota Transportation Museum
• MNWX - Minnesota Department of Public Service (Weights and Measures Division)
• MOBX - Mobil Oil Corporation; Exxon-Mobil Corporation
• MOC - Missouri Central Railroad
• MOCX - Missouri Portland Cement Company
• MOD - Missouri Pacific Railroad
• MOEX - Morgan Engineering
• MOFX - Maxton Oil and Fertilizer Company
• MOGX - C.W. Brooks
• MOHX - Monsanto Company; Solutia
• MOLU - Mitsui OSK Lines
• MOLX - International Molasses Corporation
• MON - Monon Railroad; Seaboard System Railroad; CSX Transportation
• MONX - Monsanto Company; Solutia
• MOPZ - Flexi-Van Leasing
• MORZ - Mitsui OSK Lines
• MOSX - Mosinee Paper Corporation
• MOSZ - Mitsui OSK Lines
• MOT - Marine Oil Transportation
• MOTC - Montreal Tramways
• MOTU - Monsanto
• MOTX - National Museum of Transportation
• MOTZ - Mitsui OSK Lines
• MOWX - Fortaleza Construction Company
• MOXV - Moxahala Valley Railway
• MP - Missouri Pacific Railroad; Union Pacific
• MPA - Maryland and Pennsylvania Railroad; York Railway
• MPCX - Moyer Packing Company; Michels Pipeline Construction
• MPEX - MotivePower
• MPIT - Missouri Pacific;Union Pacific
• MPIX - Myer's Propane Gas Service; MotivePower
• MPLI - Minnesota Prairie Line
• MPLX - GE Rail Services
• MPLZ - Union Pacific
• MPRX - Motive Power & Equipment Solutions
• MPSX - Missouri Public Service
• MPTX - Procor
• MPU - Missouri Pacific Railroad, Union Pacific
• MPWX - Muscatine Power and Water
• MPZ - Union Pacific
• MQCX - Monarch Cement Company
• MQGX - Morrison-Quirk Grain Corporation
• MQPX - Millennium Inorganic Chemicals
• MQRX - Macquarie Rail, Inc.; Wells Fargo Rail
• MQT - Marquette Rail
• MR - McCloud River Railroad; McLeod Railway
• MRAX - Mineral Range
• MRCX - Evans Railcar Leasing Company; GE Rail Services Corporation
• MRDX - MidAmerican Energy Company
• MREX - Marshall Railway Equipment Corporation; Monad Railway Equipment Company
• MRHS - Midland Railway
• MRI - Mohall Railroad
• MRIX - Motive Rail Industries
• MRL - Montana Rail Link
• MRMX - Midwest Railcar Corporation (previously named MRM Leasing and Management)
• MRMZ - Monticello Railway Museum
• MRR - Carolina Southern Railroad
• MRRX - GE Rail Services; Murphy Road Recycling
• MRS - Manufacturers Railway Company; Anheuser-Busch
• MRSX - Mile-High Railcar Services
• MS - Michigan Shore Railroad
• MSAX - Midwest Steel and Alloy
• MSAZ - National Motor Freight Traffic Association
• MSC - Illinois Central Gulf Railroad (Mississippi Central, Hattiesburg to Natchez)
• MSCI - Mississippi Central Railroad (Oxford to Grand Jct)
• MSCU - Mediterranean Shipping Company
• MSCZ - Mediterranean Shipping Company
• MSDR - Mississippi Delta Railroad, Rock Island Rail
• MSDU - Mediterranean Shipping Company
• MSE - Mississippi Export Railroad
• MSEX - Princess Tours
• MSIX - Morton International
• MSKU - Maersk Line
• MSL - Montgomery Short Line
• MSLC - Minnesota Short Lines Company
• MSMU - Mediterranean Shipping Company
• MSMX - Mid South Milling Company
• MSN - Meeker Southern Railroad
• MSO - Michigan Southern Railroad
• MSPX - P4 Productions
• MSQU - Military Sealift Command (Bayonne, New Jersey)
• MSR - Mississippi Southern Railroad (Watco)
• MSRC - Kansas City Southern Railway (former MidSouth Railcorp)
• MSRW - Mississippian Railway
• MSTL - Minneapolis and St. Louis Railway; Chicago & North Western Railway; Union Pacific
• MSTR - Massena Terminal Railroad
• MSTX - Steam Railroading Institute
• MSUU - USPCI
• MSV - Mississippi and Skuna Valley Railroad
• MSWY - Minnesota Southern Railway
• MT - Mississippi and Tennessee RailNet
• MTAX - MTAX Corporation
• MTC - Mystic Terminal Company
• MTCO - Macon Terminal Company
• MTCX - Mallard Transportation Company
• MTCZ - Mayflower Transit and Storage
• MTDX - Midwest Transportation and Development Company
• MTFR - Minnesota Transfer Railway
• MTIU - Welfit Oddy
• MTIZ - American Marine Industries
• MTLU - Montgomery Tank Lines
• MTLX - Metal Link International
• MTMU - March
• MTMX - Modern Track Machinery
• MTNX - Rocky Mountain Transportation Services
• MTPX - Montana Power Company
• MTR - Montour Railroad; Youngstown and Southeastern Railroad
• MTRX - TransMatrix
• MTSU - Marine Transport Service
• MTTX - Trailer Train Company; TTX Company
• MTW - Marinette, Tomahawk and Western Railroad
• MTZ - Mitsui OSK Lines; Montgomery Tank
• MTZX - Mitsui Rail Capital LLC
• MULX - MUL Railcars Leasing LLC
• MUSC - Memphis Union Station Company
• MV - Midland Valley Railroad
• MVCX - Chaparral Energy
• MVP - Missouri and Valley Park Railroad
• MVRY - Mahoning Valley Railway
• MVT - Mount Vernon Terminal
• MWAX - Martin Marietta Materials
• MWBX - Midwest By-Products Company
• MWCL - Midwest Coal Handling
• MWCX - Midwest Railcar Corporation
• MWHX - Markwest Hydrocarbon Partners
• MWLX - Midwest Locomotive Leasing and Sales
• MWLZ - Madrigal-Wan Hai Lines Corporation
• MWMX - Midwest Mud Company; Golden Leasing
• MWPX - Murco Wall Products
• MWR - Muncie and Western Railroad
• MWRC - Mount Washington Railway
• MWRL - Molalla Western Railway; Hillvista Investment Company
• MWRR - Montana Western Railway
• MWRX - Midwest Rail
• MWSX - Midwest Solvents Company; GE Rail Services
• MWTT - Michigan-Wisconsin Transportation Company
• MXLU - Mexican Line
• MZIZ - Marko B Zanovich