| — | Kemper Equipment | CGVG | Mine contractor | — |
| — | Ken & Coy Rock Inc. | CD638 | Mine contractor | — |
| — | Ken Frank Trucking | CD418 | Mine contractor | — |
| — | Ken's Towing & Service | CT017 | Mine contractor | — |
| — | Kenco General Contractor | CE035 | Mine contractor | — |
| — | Kenley Hubble LLC | CA2094 | Mine contractor | — |
| — | Kennedy Morrow Trucking | CB3895 | Mine contractor | — |
| — | Kennedy Welding | CAU4 | Mine contractor | — |
| — | Kennedy Welding LLC | CA2715 | Mine contractor | — |
| — | Kenny A. Burgess Construction L.L.C. | CYSB | Mine contractor | — |
| — | Kenny Adams Transfer | CV438 | Mine contractor | — |
| — | Kennys King Trucking LLC | CC6629 | Mine contractor | — |
| — | Kent Electric Co | CTB8 | Mine contractor | — |
| — | Kentucky Oil & Refining Co In | CATN | Mine contractor | — |
| — | Kerco Inc | CI0X | Mine contractor | — |
| — | Kern Ag Services | CB3569 | Mine contractor | — |
| — | Kerns Trucking Inc | CQN5 | Mine contractor | — |
| — | Kershner Electric LLC | CC7160 | Mine contractor | — |
| — | Ketchem Construction Company | CN9I | Mine contractor | — |
| — | Kevin Kinyon Construction | CR142 | Mine contractor | — |
| — | Kevin Smith Enterprises LLC | CB9451 | Mine contractor | — |
| — | Kevmar Company LLC | CC7727 | Mine contractor | — |
| — | Keyrock Energy Inc | CVQD | Mine contractor | — |
| — | Keystone Anthracite Co, Inc. | CP510 | Mine contractor | — |
| — | Keystone Industries Inc | CC4349 | Mine contractor | — |
| — | Keystone Pump & Power LLC | CC0382 | Mine contractor | — |
| — | Keystone Safety Consulting | CC5860 | Mine contractor | — |
| — | KHI Mechanical LLC | CB1683 | Mine contractor | — |
| — | Kidron Electric Inc. | CA5563 | Mine contractor | — |
| — | Kiel Sand & Gravel | CA2230 | Mine contractor | — |
| — | Kiewit Infrastructure South Co. | CA6316 | Mine contractor | — |
| — | Kiewit Mining Group | CZ468 | Mine contractor | — |
| — | Kiln Technology Inc. | CB8291 | Mine contractor | — |
| — | Kimball Equipment Company | CV920 | Mine contractor | — |
| — | Kimmel Mechanical, LLC | CC3040 | Mine contractor | — |
| — | Kinbro Inc | CC4151 | Mine contractor | — |
| — | Kinetic Energy Services | CC6285 | Mine contractor | — |
| — | King Construction Services Inc | CC0550 | Mine contractor | — |
| — | King Drilling LLC | CC6139 | Mine contractor | — |
| — | King's Auto Glass LLC. | CC6565 | Mine contractor | — |
| — | King'S Tire Service Inc | CGVW | Mine contractor | — |
| — | KINGS ELECTRIC INC | CC4597 | Mine contractor | — |
| — | Kinnison excavating | CC7726 | Mine contractor | — |
| — | Kinsley Construction Inc | CYPE | Mine contractor | — |
| — | Kipar Blasting | CT895 | Mine contractor | — |
| — | Kirby Smith Machinery Inc | C3HK | Mine contractor | — |
| — | Kirk Environmental, LLP | CB7194 | Mine contractor | — |
| — | KISSNER WELDING | CA5662 | Mine contractor | — |
| — | Kitchens Heavy Duty Repair, LLC. | CC6880 | Mine contractor | — |
| — | Kittanning Contractors, LLC | CA1872 | Mine contractor | — |
| — | Kleinfelder, Inc. | CZRB | Mine contractor | — |
| — | KLF Consulting & Estimating LLC | CA9741 | Mine contractor | — |
| — | Kling Ranch | CPK1 | Mine contractor | — |
| — | Klingner & Associates PC | CT574 | Mine contractor | — |
| — | KLL Equipment | CC0570 | Mine contractor | — |
| — | Klocke Inc | CA1116 | Mine contractor | — |
| — | KLS Crushing | CC7937 | Mine contractor | — |
| — | KMC | CX462 | Mine contractor | — |
| — | KMG Electric Inc. | CB2707 | Mine contractor | — |
| — | Knepco Equipment & Services | CC7026 | Mine contractor | — |
| — | Knickerbocker Leasing, LLC | CB8294 | Mine contractor | — |
| — | Knife River Materials | CB5500 | Mine contractor | — |
| — | Knife River North Central | CB0402 | Mine contractor | — |
| — | Knight Const. and Supply Inc. | CH922 | Mine contractor | — |
| — | Knight Material Technologies LLC | CKKU | Mine contractor | — |
| — | Knight Piesold & Co | CZ1G | Mine contractor | — |
| — | Knight's Companies | CC9190 | Mine contractor | — |
| — | KNS Communications Consultants | CY062 | Mine contractor | — |
| — | Kodiak Mechanical Systems, Inc. | CN974 | Mine contractor | — |
| — | Koenig Scale Company Inc. | CD180 | Mine contractor | — |
| — | Kokosing Constr Co Inc | CC5Q | Mine contractor | — |
| — | Kokosing Industrial | CB6606 | Mine contractor | — |
| — | Kolberg-pioneer inc | CB1779 | Mine contractor | — |
| — | Komatsu America Corporation | CDVR | Mine contractor | — |
| — | Kone Cranes - AZ Office | CC8138 | Mine contractor | — |
| — | Kone Inc. | CY922 | Mine contractor | — |
| — | KOORSEN PROTECTION SERVICES INC. | CMZZ | Mine contractor | — |
| — | Koplin Excavating & Grading Co | CUGB | Mine contractor | — |
| — | KOPPLIN & KINAS CO. INC. | CD969 | Mine contractor | — |
| — | Koury Transport LLC | CV316 | Mine contractor | — |
| — | Kovacs Brothers Inc | CUDT | Mine contractor | — |
| — | Kozelka Electric | CC5992 | Mine contractor | — |
| — | KP&E Electric, LLC | CC8769 | Mine contractor | — |
| — | KPI Electric | CA3603 | Mine contractor | — |
| — | Kramers Services Inc | C5IS | Mine contractor | — |
| — | Krebs Land Development, LLC | CX623 | Mine contractor | — |
| — | Krech Ojard & Associates, P. A. | CT857 | Mine contractor | — |
| — | Kreider Mechanical Inc. | CC6947 | Mine contractor | — |
| — | Kremper Mechanical LLC | CA3263 | Mine contractor | — |
| — | KRH, Inc. | CF654 | Mine contractor | — |
| — | Krist Door Service Inc | C1MU | Mine contractor | — |
| — | Kroff Chemical Co Inc | C3YN | Mine contractor | — |
| — | Ksd Diesel | C2AD | Mine contractor | — |
| — | KT Grant, Inc. | CY4E | Mine contractor | — |
| — | kucera plumbing, heating, cooling, & sheet m llc | CA4657 | Mine contractor | — |
| — | KUNA Engineering, LLC | CB8067 | Mine contractor | — |
| — | Kyle Smith Welding | CC0439 | Mine contractor | — |
| — | L & C Gravel, LLC | CA6601 | Mine contractor | — |
| — | L & H Industrial, Inc. | CJY1 | Mine contractor | — |
| — | L & H Mechanical and Electrical Services, Inc. | CC4509 | Mine contractor | — |
| — | L & L Construction Inc. | CB3992 | Mine contractor | — |
| — | L & L Contractors, Inc | CC2520 | Mine contractor | — |
| — | L & L Tire, Inc. | CA9286 | Mine contractor | — |
| — | L & M Service Contracting | CB8240 | Mine contractor | — |
| — | L A Barrier & Son Inc | CLVI | Mine contractor | — |
| — | L Beans Service LLC | CC2314 | Mine contractor | — |
| — | L D Wright & Son Trucking Inc | CDLP | Mine contractor | — |
| — | L J Hughes & Sons Inc | CD78 | Mine contractor | — |
| — | L Keeley Construction | CB8533 | Mine contractor | — |
| — | L P R | CB822 | Mine contractor | — |
| — | L. A. Perks Plumbing & Heating, Inc | CZ859 | Mine contractor | — |
| — | L. Cobb Construction, Inc. | CU748 | Mine contractor | — |
| — | L. Murphy Construction, Inc. | CA5823 | Mine contractor | — |
| — | L9 Electric LLC | CC3464 | Mine contractor | — |
| — | La Grange Landscape Supply | CC6074 | Mine contractor | — |
| — | Lacquement Scale Co. | CQ742 | Mine contractor | — |
| — | Lafarge | CA7086 | Mine contractor | — |
| — | Lafollette Utilities | CW858 | Mine contractor | — |
| — | Lake Contracting Inc | CN908 | Mine contractor | — |
| — | Lake Superior Consulting, LLC | CR754 | Mine contractor | — |
| — | Lake View Services, LLC | CB2799 | Mine contractor | — |
| — | Lakehead Constructors Inc | CAQS | Mine contractor | — |
| — | Lambert & Company Drilling Inc | CPWU | Mine contractor | — |
| — | Lambert, Inc. | CA3375 | Mine contractor | — |
| — | Lamp, Rynearson & Associates, Inc. | CA1722 | Mine contractor | — |
| — | LAND AND LAKES CO. | CE605 | Mine contractor | — |
| — | Land Care Construction LLC | CA7350 | Mine contractor | — |
| — | Landis C. Deck & Sons | CS653 | Mine contractor | — |
| — | Landis Trucking | CHH4 | Mine contractor | — |
| — | Landmark Construction, Inc. | CD642 | Mine contractor | — |
| — | Landmark Crane Company LLC dba Hook Crane Services | CC2021 | Mine contractor | — |
| — | Langford Trucking, LLC | CA4294 | Mine contractor | — |
| — | lanham drilling | CU514 | Mine contractor | — |
| — | Larimores Millwright Services LLC | CB2601 | Mine contractor | — |
| — | LaRoche Tree Service, Inc. | CC2594 | Mine contractor | — |
| — | Laron Inc | CF996 | Mine contractor | — |
| — | Larry E. Speaks & Associates, Inc. | CY648 | Mine contractor | — |
| — | Larry LaRue Mechanic | CC8761 | Mine contractor | — |
| — | Las Vegas Paving Co | CD6P | Mine contractor | — |
| — | Latis Environmental, LLC | CC8403 | Mine contractor | — |
| — | LATONA TRUCKING, INC | CL483 | Mine contractor | — |
| — | Lawnrangerprofessional Landscaping | CB5933 | Mine contractor | — |
| — | Lawson Drilling Company LLC | CQ380 | Mine contractor | — |
| — | Lawson Products Inc. | CD342 | Mine contractor | — |
| — | Lawson Rich Environmental Services | CC9243 | Mine contractor | — |
| — | Lawson's Welding Service | CW609 | Mine contractor | — |
| — | Lay'S Mining Service | CZEP | Mine contractor | — |
| — | Layne Christensen Company | CPU3 | Mine contractor | — |
| — | LD Welding LLC | CC6620 | Mine contractor | — |
| — | LDE Corporation | CD994 | Mine contractor | — |
| — | Leaaf Environmental, LLC | CD0225 | Mine contractor | — |
| — | Lead Ram Consulting, LLC | CC8776 | Mine contractor | — |
| — | Leak Location Services Inc | CWLD | Mine contractor | — |
| — | Lebanon Machine Shop Inc | CVQL | Mine contractor | — |
| — | Lebe Drilling & Blasting Inc | CB6063 | Mine contractor | — |
| — | Ledcor CMI Inc. | CR810 | Mine contractor | — |
| — | Lee Electrical Const. | CY483 | Mine contractor | — |
| — | Lee Hydraulic Service Inc. DBA PIRTEK Macon | CC5540 | Mine contractor | — |
| — | Lee Mar Building & Const Corp | C7TM | Mine contractor | — |
| — | Lee Mechanical Contractors Inc | CHUW | Mine contractor | — |
| — | Lee Reger Builds Inc | CR5Z | Mine contractor | — |
| — | Lee Sartin Trucking Co Inc | CZP8 | Mine contractor | — |
| — | Lee's Landscaping and Grading | CB2425 | Mine contractor | — |
| — | Lee-Rogers Tire Company | CJFZ | Mine contractor | — |
| — | Lee-Way Electrical LLC | CC6860 | Mine contractor | — |
| — | LEGACY COAL TRANSPORT LLC | CC8248 | Mine contractor | — |
| — | Legacy Drilling & Blasting,LLC | CC3226 | Mine contractor | — |
| — | Legacy Drilling LLC | CC6137 | Mine contractor | — |
| — | Legacy Geosciences | CC9285 | Mine contractor | — |
| — | Legacy Machinery | CA9943 | Mine contractor | — |
| — | Legacy Trucking | CB3715 | Mine contractor | — |
| — | Legarza Exploration | CQIL | Mine contractor | — |
| — | Legend Services, Inc | CC1339 | Mine contractor | — |
| — | Legends Construction Company, LLC | CC8156 | Mine contractor | — |
| — | Legion Field Service LLC | CC7300 | Mine contractor | — |
| — | Lehigh Industrial Maintenance LLC | CB4746 | Mine contractor | — |
| — | Lehigh Valley Site Contrs Inc | C3HT | Mine contractor | — |
| — | Lehigh Valley Technical Associates, Inc. | CK889 | Mine contractor | — |
| — | Leica Geosystems Inc | CG912 | Mine contractor | — |
| — | Lemke Stone | CU2R | Mine contractor | — |
| — | les rogers | CC8369 | Mine contractor | — |
| — | Les Schwab Tire Centers | CC005 | Mine contractor | — |
| — | Leslie Equipment Co | CMUT | Mine contractor | — |
| — | Lester Brothers Logging LLC | CC3240 | Mine contractor | — |
| — | Lewis Electrical Constructors, Inc. | CT684 | Mine contractor | — |
| — | Lewis Mobile Welding LLC | CB8095 | Mine contractor | — |
| — | Lexington Coal Company, LLC | CB6845 | Mine contractor | — |
| — | Leyva Construction Services, LLC. | CA8932 | Mine contractor | — |
| — | LG WELDING AND SERVICES | CC1739 | Mine contractor | — |
| — | LGG Industrial, Inc. | CARK | Mine contractor | — |
| — | LGS Global, LLC | CB3434 | Mine contractor | — |
| — | Liberty Electric, Inc | CX437 | Mine contractor | — |
| — | Liberty Fire Equipment, Inc. | CX215 | Mine contractor | — |
| — | Liberty Tire Services Of Ohio | CC6968 | Mine contractor | — |
| — | Lieber Construction, Inc. | CC7380 | Mine contractor | — |
| — | Liebherr Mining Equipment Newport News Co | CVPM | Mine contractor | — |
| — | Life Cycle Geo, LLC | CC6026 | Mine contractor | — |
| — | Lift Incorporated | CC1548 | Mine contractor | — |
| — | LiftOne, LLC | CC6849 | Mine contractor | — |
| — | Ligonier Construction Company | CD361 | Mine contractor | — |
| — | Limestone Dust Corporation | CX651 | Mine contractor | — |
| — | Lincoln Contr & Equip Co Inc | CL70 | Mine contractor | — |
| — | Linde Inc | CTQH | Mine contractor | — |
| — | Linder Industrial Machinery Co | CMGG | Mine contractor | — |
| — | Lindey & Sons Inc. | CA5979 | Mine contractor | — |
| — | Lindskov Mine Service LLC | CC8791 | Mine contractor | — |
| — | Line Power Mfg Corp | CZGJ | Mine contractor | — |
| — | Link In-Out LLC | CC9997 | Mine contractor | — |
| — | Link-Belt Construction Equipment | CA3919 | Mine contractor | — |
| — | Linkan Engineering | CA7728 | Mine contractor | — |
| — | Linton Solutions, LLC | CT658 | Mine contractor | — |
| — | Lintons Mechanical, LLC | CV5T | Mine contractor | — |
| — | Lintz Enterprises LLC | CC1358 | Mine contractor | — |
| — | Litman Excavating, Inc. | CJ785 | Mine contractor | — |
| — | Little River Construction LLC. | CB4793 | Mine contractor | — |
| — | Little River Materials | CC2952 | Mine contractor | — |
| — | Little Si's Construction Inc. | CD0243 | Mine contractor | — |
| — | Little's Heating & Air Conditioning, Inc | CW848 | Mine contractor | — |
| — | Litzenberger Construction, Inc. | CB6142 | Mine contractor | — |
| — | Live Wire Electric Inc | CC3033 | Mine contractor | — |
| — | LJ Inc | CA1578 | Mine contractor | — |
| — | LL Brown | CA3405 | Mine contractor | — |
| — | llA Lab Services, LLC | CH557 | Mine contractor | — |
| — | Lloyd Environmental Services | CD806 | Mine contractor | — |
| — | Lloyd W Aubry Co Inc | CY4Z | Mine contractor | — |
| — | LM Wright Trucking Inc. | CC6888 | Mine contractor | — |
| — | LMB Industrial Services, Inc. | CS914 | Mine contractor | — |
| — | LMC Training and Consulting, LLC | CC7448 | Mine contractor | — |
| — | Loadrite East Texas Inc. | CA5481 | Mine contractor | — |
| — | LOADRITE Southern Star LLC | CB7519 | Mine contractor | — |
| — | Locust Ridge Contractors | CS650 | Mine contractor | — |
| — | LoDebar Inc. | CG001 | Mine contractor | — |
| — | Loenbro | CP276 | Mine contractor | — |
| — | Logical Systems, LLC | CA9077 | Mine contractor | — |
| — | Logix Automation Ltd | CC6893 | Mine contractor | — |
| — | Logos Logistics LLC | CC2236 | Mine contractor | — |
| — | Loikits Industrial Services | CQ562 | Mine contractor | — |
| — | Lone Mountain Repair LLC | CC0059 | Mine contractor | — |
| — | Lone Star Railroad Contractors, Inc. | CH742 | Mine contractor | — |
| — | Lonestar Fencing & Excavation | CB3184 | Mine contractor | — |
| — | Lonestar Sierra, LLC | CB4231 | Mine contractor | — |
| — | Long Run Transport | CZXG | Mine contractor | — |
| — | Longo Electrical-Mechanical, Inc. | CM739 | Mine contractor | — |
| — | Loos Service & Supply, Inc. | CT292 | Mine contractor | — |
| — | Lopke Quarries Inc | CASI | Mine contractor | — |
| — | Lord's Fence, Inc. | CC8564 | Mine contractor | — |
| — | Losada Consulting Inc. | CB4972 | Mine contractor | — |
| — | Loudermilk Contracting, Inc. | CP4D | Mine contractor | — |
| — | LOUDWIRE DIESEL LLC | CB7551 | Mine contractor | — |
| — | Louie'S Trenching Service Inc | CC136 | Mine contractor | — |
| — | Louisiana Machinery | CIHT | Mine contractor | — |
| — | Louisiana Radio Communications, Inc. | CB1172 | Mine contractor | — |
| — | Loureiro Contractors, Inc. | CC8620 | Mine contractor | — |
| — | LR Falk Construction Company | CC4931 | Mine contractor | — |
| — | LRS, Inc. | CC9763 | Mine contractor | — |
| — | Lube Specialists | CA1816 | Mine contractor | — |
| — | Lucas Turner's welding | CC7284 | Mine contractor | — |
| — | Luck Eco Systems | CA8727 | Mine contractor | — |
| — | Luck Stone Corp(Constr Div) | CAFF | Mine contractor | — |
| — | Luck Stone Special Serv Grp | C9LB | Mine contractor | — |
| — | Luckett Crane Service | CZ306 | Mine contractor | — |
| — | Lucky S Diesel Equipment Service | CC9197 | Mine contractor | — |
| — | Lucky Seven Trucking / Leonardo Olivo | CC7048 | Mine contractor | — |
| — | Ludwig Explosives Inc | CB1N | Mine contractor | — |
| — | Lufkin Rubber and Gasket | CB2124 | Mine contractor | — |
| — | Luker Brothers, Inc. | C6KS | Mine contractor | — |
| — | Luke¿s Welding | CC8448 | Mine contractor | — |
| — | Lumix Electrical, Inc. | CB6481 | Mine contractor | — |
| — | Lumpkin Industries | CJ890 | Mine contractor | — |
| — | Lusk Disposal | CXSY | Mine contractor | — |
| — | Lutgring Bros., Inc. | CL182 | Mine contractor | — |
| — | Lyle Machinery Co. | CA513 | Mine contractor | — |
| — | Lyman & Ryerson Electric | CT375 | Mine contractor | — |
| — | Lynn Thomas Grading, Inc. | CQ092 | Mine contractor | — |
| — | Lynn Whitsett Corp | CFET | Mine contractor | — |
| — | Lyons Welding and Fabrication | CC3140 | Mine contractor | — |
| — | M & J Explosives LLC | CA373 | Mine contractor | — |
| — | M & J Trucking Co Inc | CEYH | Mine contractor | — |
| — | M & M Excavating Inc. | CM430 | Mine contractor | — |
| — | M & M Excavation CO | CC4925 | Mine contractor | — |
| — | M & R Trucking and Excavating | CB2792 | Mine contractor | — |
| — | M & S Blasting LLC | CB1579 | Mine contractor | — |
| — | M & S PhotoDraft LLC | CC8701 | Mine contractor | — |
| — | M A Heston Inc | CB48 | Mine contractor | — |
| — | M and M Equipment Repair LLC | CC5830 | Mine contractor | — |
| — | M C Donegan LLC | CY627 | Mine contractor | — |
| — | M G C Inc | CKZ6 | Mine contractor | — |
| — | M J Trucking & Contracting | CA730 | Mine contractor | — |
| — | M J Van Damme Trucking Inc. | C2EE | Mine contractor | — |
| — | M Lange's welding | CB8052 | Mine contractor | — |
| — | M Miller HVAC INC | CC9909 | Mine contractor | — |
| — | M P Electric, Inc. | C2HX | Mine contractor | — |
| — | M P Environmental Services Inc | CLEN | Mine contractor | — |
| — | M S I Construction Co Inc | CAY5 | Mine contractor | — |
| — | M S Industrial Corporation | CJ103 | Mine contractor | — |
| — | M&B Equipment Repair | CB1384 | Mine contractor | — |
| — | M&C TRUCKING CO. | CJ265 | Mine contractor | — |
| — | M&H Construction | CXDU | Mine contractor | — |
| — | M&H Facility Operations, Inc. | CA9673 | Mine contractor | — |
| — | M&m dirt Llc | CC5716 | Mine contractor | — |