| — | Minnesota Valley Testing Laboratories, Inc. | CB2291 | Mine contractor | — |
| — | Minnkota Power Cooperative Inc | CUXP | Mine contractor | — |
| — | Minot Enterprises, Inc. | CC8869 | Mine contractor | — |
| — | Minova USA Inc. | CXCX | Mine contractor | — |
| — | Mintech Enterprises, LLC | CZ685 | Mine contractor | — |
| — | Miron Construction Co Inc | C3VS | Mine contractor | — |
| — | Miscisin Engineering and Consulting | CC3148 | Mine contractor | — |
| — | Mississippi Lime Company | CA6754 | Mine contractor | — |
| — | Mister C Mobile Pressure | CD4N | Mine contractor | — |
| — | Mitchell ETPS LLC | CC6283 | Mine contractor | — |
| — | Mitchell Products | CA7353 | Mine contractor | — |
| — | MItchell Rock | CC0885 | Mine contractor | — |
| — | MitRes Services, LLC | CC3435 | Mine contractor | — |
| — | MJ Crane Works | CC7597 | Mine contractor | — |
| — | MJ MECHANICAL HEATING & AIR CONDITIONING | CB3698 | Mine contractor | — |
| — | MJ Track Work Inc. | CW593 | Mine contractor | — |
| — | MJD Metal Works | CC2485 | Mine contractor | — |
| — | MJM Electric, Inc. | CQ121 | Mine contractor | — |
| — | MJM Welding | CB0680 | Mine contractor | — |
| — | ML Logging LLC | CC9682 | Mine contractor | — |
| — | MLC PROCESS AND DESIGN LLC | CC0942 | Mine contractor | — |
| — | MLC Services, LLC | CB9273 | Mine contractor | — |
| — | MLJ Trucking | CX641 | Mine contractor | — |
| — | MM Quarries | CC8326 | Mine contractor | — |
| — | MMD Mineral Sizing (America) Inc. | CB9664 | Mine contractor | — |
| — | MMR Constructors Inc. | CM837 | Mine contractor | — |
| — | mn construction | CA3158 | Mine contractor | — |
| — | MobiCon Crushing and Recycling, LLC | CA7507 | Mine contractor | — |
| — | Mobile Communications America | CB7595 | Mine contractor | — |
| — | Mobile Equipment Air Conditioning, LLC | CK907 | Mine contractor | — |
| — | Mobile Equipment Services, LLC | CC2271 | Mine contractor | — |
| — | Mobile Equipment Solutions LLC | CB6817 | Mine contractor | — |
| — | Mobile Maintenance Team LLC | CC8071 | Mine contractor | — |
| — | Mobile Mechanics - Vulcan | CC9241 | Mine contractor | — |
| — | Mobile Transport Services Inc | CB1009 | Mine contractor | — |
| — | MOBILE TRUCK AND TRAILER REPAI | CC9347 | Mine contractor | — |
| — | Modern | CC8603 | Mine contractor | — |
| — | Modern Control Solutions, LLC | CB9631 | Mine contractor | — |
| — | Modern Crane Service | CN265 | Mine contractor | — |
| — | Modern Equipment, Inc. | CR579 | Mine contractor | — |
| — | Modern Machine Works Inc | CHT4 | Mine contractor | — |
| — | Modern Machinery Inc | CB642 | Mine contractor | — |
| — | Modern Solutions Texas LLC | CC9888 | Mine contractor | — |
| — | Mohave Construction Services, LLC | CC3388 | Mine contractor | — |
| — | Mohl Drilling Inc | CU74 | Mine contractor | — |
| — | Mole Master Services Corp | CV2T | Mine contractor | — |
| — | Moltz Construction, Inc. | CP247 | Mine contractor | — |
| — | Mommas Cleaning Service | CA4208 | Mine contractor | — |
| — | Mon Valley Integration L.L.C. | CF338 | Mine contractor | — |
| — | Monarch Stone Company Inc | CB3055 | Mine contractor | — |
| — | Montana Minerals Trans Llc | CRQL | Mine contractor | — |
| — | MONTELL FABRICATION & REBUILD, LLC | CB0638 | Mine contractor | — |
| — | Montgomery welding services LLC | CC3863 | Mine contractor | — |
| — | Montrose County | CP636 | Mine contractor | — |
| — | Montrose Glass | CR306 | Mine contractor | — |
| — | Moody Construction Services In | CB481 | Mine contractor | — |
| — | Moody Engineering, Inc. | CZ470 | Mine contractor | — |
| — | Mooney Crane | CJ306 | Mine contractor | — |
| — | MOORES CRANE RENTAL | CJ849 | Mine contractor | — |
| — | Moores Electrical & Mechanical | CA9949 | Mine contractor | — |
| — | Moores Grading | CA7376 | Mine contractor | — |
| — | MOR-PPM Inc | CG908 | Mine contractor | — |
| — | Moran Mining Usa Inc | C4MC | Mine contractor | — |
| — | Morgan Corp | CAIR | Mine contractor | — |
| — | Morgan Inc Contractors | CFNK | Mine contractor | — |
| — | Morgantown Machne & Hydraulics-WV | CN524 | Mine contractor | — |
| — | Morgantown Septic Service Portable Toilet Rentals | CA2723 | Mine contractor | — |
| — | Morgantown Technical Services | C9XU | Mine contractor | — |
| — | Morlandt Electric Company | CIZF | Mine contractor | — |
| — | Morris Strategies | CC8047 | Mine contractor | — |
| — | Morrison Metalweld Process Cor | CGYF | Mine contractor | — |
| — | Morrow Railroad Builders | CA117 | Mine contractor | — |
| — | Morrow Water Technologies | CS246 | Mine contractor | — |
| — | Mossy Creek Mining LLC | CY659 | Mine contractor | — |
| — | Mostardi Platt | CA1162 | Mine contractor | — |
| — | Motion Industries, Inc. | CQ650 | Mine contractor | — |
| — | Motive Care & Supply, Inc. | CB6403 | Mine contractor | — |
| — | Motive Rail Inc | CB225 | Mine contractor | — |
| — | Motor Technology Inc | CB942 | Mine contractor | — |
| — | Mott MacDonald | CLPF | Mine contractor | — |
| — | Mouldagraph Corp | CM7U | Mine contractor | — |
| — | Mountain Crane Service | CA2492 | Mine contractor | — |
| — | Mountain Creek Sand LLC | CC2338 | Mine contractor | — |
| — | Mountain Industrial Power | CF635 | Mine contractor | — |
| — | Mountain Lake Electric | CB921 | Mine contractor | — |
| — | Mountain Power Electric Inc. | CC4822 | Mine contractor | — |
| — | Mountain Regional Equipment Solutions Inc | CA2317 | Mine contractor | — |
| — | Mountain Research, LLC | CY235 | Mine contractor | — |
| — | Mountain Safety Service | CB2936 | Mine contractor | — |
| — | Mountain State Contracting & Environmental Service | CC1667 | Mine contractor | — |
| — | Mountain State Rail Services, Inc. | CT331 | Mine contractor | — |
| — | Mountain State Security, LLC | CA9061 | Mine contractor | — |
| — | Mountain States Contracting In | CNJQ | Mine contractor | — |
| — | Mountain States Mine Development & Reclamation LLC | CC6168 | Mine contractor | — |
| — | Mountain Top Equipment Repair LLC | CC6984 | Mine contractor | — |
| — | Mountain Valley Professionals, LLC | CC9736 | Mine contractor | — |
| — | Mountain West Electric, Inc. | CQ467 | Mine contractor | — |
| — | Mountain West Industrial | CB1515 | Mine contractor | — |
| — | Mountaineer Contractors, Inc. | CX616 | Mine contractor | — |
| — | Mountaineer Excavating Inc | CB52 | Mine contractor | — |
| — | Mountaineer Harvesting | CC5397 | Mine contractor | — |
| — | Mountaineer Investigation & Security, Inc. | C4AV | Mine contractor | — |
| — | Mountaineer Specialty LLC | CC6186 | Mine contractor | — |
| — | Mountaineer Welding | CM248 | Mine contractor | — |
| — | Mountaintop Clearing LLC | CC858 | Mine contractor | — |
| — | Mover Drilling LLC | CN267 | Mine contractor | — |
| — | Moyer Excavating LLC | CC7665 | Mine contractor | — |
| — | MP Predictive Technologies Inc. | CB8221 | Mine contractor | — |
| — | MP Systems | CB6623 | Mine contractor | — |
| — | MPI Contracting Services | CD0232 | Mine contractor | — |
| — | MPW Industrial Services | CW1J | Mine contractor | — |
| — | Mr. Green Jeans Lawn Services | CC5889 | Mine contractor | — |
| — | MRR Welding & Contracting Services | CC9391 | Mine contractor | — |
| — | MSALABS USA Inc | CC7012 | Mine contractor | — |
| — | MSC Earthwork, LLC | CB8559 | Mine contractor | — |
| — | MSE Electric Inc. | CQ013 | Mine contractor | — |
| — | MSE LLC | CA6394 | Mine contractor | — |
| — | MSHA Safety Services | CC1661 | Mine contractor | — |
| — | MT Mine EHS Consulting | CC3270 | Mine contractor | — |
| — | Mt Pleasant Mine Service LLC | CRLH | Mine contractor | — |
| — | MTM ELECTRIC, LLC | CC4842 | Mine contractor | — |
| — | Mtn States Fence Company Inc | CP9Q | Mine contractor | — |
| — | Mulgrew Oil Company, dba Perfection Oil Company | CF678 | Mine contractor | — |
| — | Mullenix Machining and Welding | CC9862 | Mine contractor | — |
| — | Muller Construction | CC2069 | Mine contractor | — |
| — | Multi-Craft Contractors, Inc. | CK671 | Mine contractor | — |
| — | Municipal Well & Pump | CA6765 | Mine contractor | — |
| — | Murphy Elevator Co | CA74 | Mine contractor | — |
| — | Murphy Tractor & Eq. Co. | CD598 | Mine contractor | — |
| — | Murphy's Bobcat Inc | CC7846 | Mine contractor | — |
| — | Murray Transport | CEX7 | Mine contractor | — |
| — | Murrill Electric LLC | CZMX | Mine contractor | — |
| — | Murrysville Machinery Co., LLC | CZ109 | Mine contractor | — |
| — | Mustang Aerial Services Inc | CB3731 | Mine contractor | — |
| — | Mustang Extreme Environmental Services, LLC | CC2509 | Mine contractor | — |
| — | Mustang Tractor & Equipment | CPKC | Mine contractor | — |
| — | Muth Electric Inc | CHLJ | Mine contractor | — |
| — | MVTC, LLC dba Madisonville Tire | CC6739 | Mine contractor | — |
| — | MW Industrial Services, Inc | CV560 | Mine contractor | — |
| — | Myers Brothers Drilling Contr | CMIR | Mine contractor | — |
| — | Myers Electric | CB8675 | Mine contractor | — |
| — | Myers Trucking | CA3344 | Mine contractor | — |
| — | Myles Lorentz, Inc. | CA8929 | Mine contractor | — |
| — | MZP Kiln Services, Inc. | CB1636 | Mine contractor | — |
| — | N A Degerstrom Inc | CAT0 | Mine contractor | — |
| — | N C Machinery Co | CC5Y | Mine contractor | — |
| — | N&W Landscaping | CB1614 | Mine contractor | — |
| — | N. D. Williams Timber Co. | CL214 | Mine contractor | — |
| — | Nacirema Demolition and Recycling, Inc. | CB8941 | Mine contractor | — |
| — | NAK Construction Services, LLC. dba NAK Kiln | CL829 | Mine contractor | — |
| — | Nalco Co. - Mining Group | CTW6 | Mine contractor | — |
| — | Nally & Hamilton Enterprises | CZZD | Mine contractor | — |
| — | Nana Construction | CB6613 | Mine contractor | — |
| — | Nansemond Lawn and Landscaping, Inc. | CC3776 | Mine contractor | — |
| — | Naquin Precision Earth Moving | CQ996 | Mine contractor | — |
| — | Nasco Industrial Services and Supply, LLC | CB5151 | Mine contractor | — |
| — | Nashville Rubber & Gasket Co., Inc. | CE697 | Mine contractor | — |
| — | National Equipment Dealers | CC4115 | Mine contractor | — |
| — | National EWP, Inc | CA0509 | Mine contractor | — |
| — | National Railroad Constr Inc | CA3H | Mine contractor | — |
| — | National Tank and Equipment, LLC | CC2199 | Mine contractor | — |
| — | Nationwide Belting Sales and Service | CB7156 | Mine contractor | — |
| — | Nationwide Boiler Inc. | CC1814 | Mine contractor | — |
| — | Nationwide Fiberoptic And Power LLC. | CC1600 | Mine contractor | — |
| — | Natural Resources Management, LLC | CB1506 | Mine contractor | — |
| — | Navco Construction | CA7119 | Mine contractor | — |
| — | Nave Fabrication LLC | CB5198 | Mine contractor | — |
| — | NC Department of Labor | CC1255 | Mine contractor | — |
| — | NCH Corporation d/b/a Certified Laboratories | CC0532 | Mine contractor | — |
| — | NE drill services LLC | CC1547 | Mine contractor | — |
| — | Neal & Associates Inc | CTRC | Mine contractor | — |
| — | Nebraska Iowa Supply Company | CC8358 | Mine contractor | — |
| — | Neier Inc | CA6759 | Mine contractor | — |
| — | Neil's Controlled Blasting, LP | CIRD | Mine contractor | — |
| — | Neil's Welding | CE119 | Mine contractor | — |
| — | Neilsen Exploration LLC | CC4985 | Mine contractor | — |
| — | Neiswonger Construction, Inc. | CD503 | Mine contractor | — |
| — | Nelson Brothers LLC - Southern Region | CB5225 | Mine contractor | — |
| — | Nelson Brothers LLC Appalchia Region | CB5227 | Mine contractor | — |
| — | Nelson Brothers LLC Midwest Region | CB5228 | Mine contractor | — |
| — | Nelson Brothers Mining Services LLC | C2ZU | Mine contractor | — |
| — | Nelson Electric Motor Service, Inc. | CL108 | Mine contractor | — |
| — | Nelson Industrial Coatings, LLC | CC5925 | Mine contractor | — |
| — | Nelson Oil Company | CA1674 | Mine contractor | — |
| — | Nelson Quarries, Inc. | CB4833 | Mine contractor | — |
| — | Nemmer Electric, Inc. | CG984 | Mine contractor | — |
| — | Neo Electrical Solutions, LLC | CC6718 | Mine contractor | — |
| — | Nerospec USA CORP | CC8257 | Mine contractor | — |
| — | Neuco Distributors | CZ514 | Mine contractor | — |
| — | New Berlin Grading, Inc. | CK624 | Mine contractor | — |
| — | New Era Consulting Services | CA5889 | Mine contractor | — |
| — | New Era Refractory LLC | CC6414 | Mine contractor | — |
| — | New Horizons Co-Op | C9AK | Mine contractor | — |
| — | New Penn Equipment LLC | CC5150 | Mine contractor | — |
| — | New River Engineers | C8BE | Mine contractor | — |
| — | New River Safety Training, LLC | CC2984 | Mine contractor | — |
| — | NewFields Mining Design & Tech services, LLC | CA6563 | Mine contractor | — |
| — | Newkirk Electric Associates Ic | CIA1 | Mine contractor | — |
| — | Newton Construction LLC | CC9855 | Mine contractor | — |
| — | NexGen Industrial Services Inc. | CA2537 | Mine contractor | — |
| — | Next Level Service | CC9994 | Mine contractor | — |
| — | Nexton Joint Venture, LLC | CC0555 | Mine contractor | — |
| — | Nexton Mining, Inc. | CN931 | Mine contractor | — |
| — | NFI/Cal Cartage | C8KK | Mine contractor | — |
| — | NH Communication & Electrical | CB7827 | Mine contractor | — |
| — | Nicely's Construction & Excavating, Inc. | CT902 | Mine contractor | — |
| — | Nickerson Company Inc | CB7872 | Mine contractor | — |
| — | Nickolas Savko & Sons Inc | C8QI | Mine contractor | — |
| — | Nielsen's Arc Service | CE435 | Mine contractor | — |
| — | Nighthawk Security Co, LLC | CB4750 | Mine contractor | — |
| — | Ninyo & Moore | CK369 | Mine contractor | — |
| — | NLS Asphalt, Paving and Transport | CC7619 | Mine contractor | — |
| — | NLT Digital Solutions, NA | CC7176 | Mine contractor | — |
| — | NMC | CIS3 | Mine contractor | — |
| — | NNE Construction, Inc. | CK936 | Mine contractor | — |
| — | No downtime equipment repair llc | CC9380 | Mine contractor | — |
| — | Noah Horn Well Drilling Co | CIM7 | Mine contractor | — |
| — | Noah's Arc | CB8773 | Mine contractor | — |
| — | Noble & Son Trucking | CRAX | Mine contractor | — |
| — | Noble Coal, LLC. | CB8610 | Mine contractor | — |
| — | Noble Excavating | CKVS | Mine contractor | — |
| — | Noel Welding LLC | CB1325 | Mine contractor | — |
| — | Nolder Excavating LLC | CC3300 | Mine contractor | — |
| — | Nondestructive Inspsvcinc | CHVB | Mine contractor | — |
| — | NOR-OH Welding, LLC | CA6912 | Mine contractor | — |
| — | NorCal Central Services | CC5436 | Mine contractor | — |
| — | Norco, Inc. | CC911 | Mine contractor | — |
| — | Norda Stelo | CC1904 | Mine contractor | — |
| — | Nordic Contracting Inc. | CC2528 | Mine contractor | — |
| — | Nordmin Engineering USA, INC | CB8878 | Mine contractor | — |
| — | Normet Americas Inc. | CB3719 | Mine contractor | — |
| — | Norrell Construction | CC7638 | Mine contractor | — |
| — | NORRIS SCREEN & MANUFACTURING, LLC | CA4169 | Mine contractor | — |
| — | North American Drillers, LLC | CH2Q | Mine contractor | — |
| — | North American Electric, Inc. | CR037 | Mine contractor | — |
| — | North American Millwright Services, Inc. | CN492 | Mine contractor | — |
| — | North American Mining Company | CVBX | Mine contractor | — |
| — | North American Recycling and Crushing LLC. | CC5338 | Mine contractor | — |
| — | North American Relines | CC6288 | Mine contractor | — |
| — | North Brunswick Electrical Contractors, Inc. | CA8696 | Mine contractor | — |
| — | North Central States Construction | CC4571 | Mine contractor | — |
| — | North Florida Drilling | CTAJ | Mine contractor | — |
| — | North Georgia Millwright | CA3433 | Mine contractor | — |
| — | North Jackson Company | CA3446 | Mine contractor | — |
| — | North MS Land Workz | CC7724 | Mine contractor | — |
| — | North Pole Coal | CT492 | Mine contractor | — |
| — | NORTH SANTIAM PAVING CO | CC5158 | Mine contractor | — |
| — | North Shore Track Constructors/Services, Inc. | CG030 | Mine contractor | — |
| — | North Star Power Inc. | CC7884 | Mine contractor | — |
| — | North States Crane & Hoist | C2TI | Mine contractor | — |
| — | North Texas Fab, LLC | CW307 | Mine contractor | — |
| — | North western Steel | CC9208 | Mine contractor | — |
| — | Northamerican Industrial Service DBA Evergreen Nor | C1WA | Mine contractor | — |
| — | Northeast Asphalt Inc | CB472 | Mine contractor | — |
| — | Northeast Technical Servs Inc | C2LI | Mine contractor | — |
| — | Northern Coatings Inc. | CF103 | Mine contractor | — |
| — | Northern Colorado Constructors Inc. | CB2775 | Mine contractor | — |
| — | Northern Concrete LLC | CC4758 | Mine contractor | — |
| — | Northern Environmental Services, Inc. | CF492 | Mine contractor | — |
| — | Northern Illinois Services Company | C2FV | Mine contractor | — |
| — | Northern Industrial Construction, Inc. | CK253 | Mine contractor | — |
| — | NORTHERN INDUSTRIAL ERECTORS, INC. | CP3V | Mine contractor | — |
| — | Northern Mechanical Services I | C5CY | Mine contractor | — |
| — | Northern MN Natural Stone | CB1724 | Mine contractor | — |
| — | Northern Partners Cooperative | CA2070 | Mine contractor | — |
| — | Northern Process Systems Inc. | CA1971 | Mine contractor | — |
| — | Northern Tires Inc | C4MZ | Mine contractor | — |
| — | Northern Valley Electrical Service Inc. | CC0723 | Mine contractor | — |
| — | Northern Virginia Drilling In | C2AW | Mine contractor | — |
| — | Northfork Construction Co. | CN921 | Mine contractor | — |
| — | Northside Welding & Fabrication Inc | CZLE | Mine contractor | — |
| — | Northstar Demolition & Remediation | CP574 | Mine contractor | — |
| — | Northwest Colorado Consultants, Inc. dba NWCC Inc. | CA6095 | Mine contractor | — |
| — | Northwest Concrete Products LLC | CC8696 | Mine contractor | — |
| — | Northwest Crane Service, LLC | CD581 | Mine contractor | — |
| — | Northwest Drill Services, LLC. | CC9783 | Mine contractor | — |
| — | Northwest Energetic Services, LLC | C6KX | Mine contractor | — |
| — | Northwest Linings Geotextile | CV6C | Mine contractor | — |
| — | Northwest Mechanical Inc. | CL237 | Mine contractor | — |
| — | Northwest Tool Repair, Corp. | CA4508 | Mine contractor | — |
| — | Northwind Enterprises | CA554 | Mine contractor | — |
| — | NORWEST INDUSTRIAL | CB5560 | Mine contractor | — |
| — | Nothnagle Drilling | CV1D | Mine contractor | — |
| — | Nott Precision Maintenance LLC | CC7919 | Mine contractor | — |
| — | Novak Diesel Service | CC4862 | Mine contractor | — |
| — | Novaspect | CA8352 | Mine contractor | — |
| — | Novinger's Welding | CE771 | Mine contractor | — |
| — | NOVUS Glass | CA1871 | Mine contractor | — |
| — | NPK Construction Equipment Inc. | CA6586 | Mine contractor | — |
| — | NQS Drilling & Blasting dba Two Eight | CC2105 | Mine contractor | — |
| — | NS Trucking LLC | CC2937 | Mine contractor | — |
| — | NSK Services, Inc. | CA4696 | Mine contractor | — |
| — | NuBlu Innovations LLC | CB8464 | Mine contractor | — |
| — | Nugent Organics LLC | CB0588 | Mine contractor | — |
| — | Nunezmachineshop INC. | CA8610 | Mine contractor | — |
| — | Nuton, LLC | CC7688 | Mine contractor | — |
| — | Nutt Trucking Inc | C9CA | Mine contractor | — |
| — | NVB Equipment | CA903 | Mine contractor | — |
| — | NW Construction, Inc. | CB8876 | Mine contractor | — |
| — | O & M Industries | CLGH | Mine contractor | — |