| — | C.T. Purcell Excavating, Inc. | CP929 | Mine contractor | — |
| — | C4 Contracting, LLC | CA8445 | Mine contractor | — |
| — | C4 Mechanical LLC | CC2209 | Mine contractor | — |
| — | CA Boone Construction, Inc, | CU664 | Mine contractor | — |
| — | Cahaba Electric Inc | CRUN | Mine contractor | — |
| — | Cal-Nevada Precision Blasting Inc. | CE814 | Mine contractor | — |
| — | Calcination & Comminution Consulting Services | CB5769 | Mine contractor | — |
| — | Caldwell Industrial Services, Inc. | CC7909 | Mine contractor | — |
| — | Caliber Field Services, Inc | CC2597 | Mine contractor | — |
| — | California Drilling & Blasting LLC | CUD9 | Mine contractor | — |
| — | California Industrial Rubber | CC686 | Mine contractor | — |
| — | Call & Nicholas Inc | CVX6 | Mine contractor | — |
| — | Calli Trucking Inc | CRBJ | Mine contractor | — |
| — | Callies Industries LLC | CA9121 | Mine contractor | — |
| — | Caltrol, Inc. | CU903 | Mine contractor | — |
| — | Camp Creek Electric LLC | CC2782 | Mine contractor | — |
| — | Campbell, Inc. | CD971 | Mine contractor | — |
| — | Camus Electric | CC6969 | Mine contractor | — |
| — | Canadian Right of Way Clearing, Inc. | CK874 | Mine contractor | — |
| — | Canary Systems, Inc. | CB5844 | Mine contractor | — |
| — | Cando Rail and Terminals | CC9853 | Mine contractor | — |
| — | Caney Creek Contracting Inc | CAJT | Mine contractor | — |
| — | Canfield Engineering & Integration | CB7053 | Mine contractor | — |
| — | Cann Enterprises, Inc | CB4547 | Mine contractor | — |
| — | CanServ LLC | CB3799 | Mine contractor | — |
| — | Canyon Concrete, Inc. | CZ648 | Mine contractor | — |
| — | Canyon Construction Co | CGKH | Mine contractor | — |
| — | Canyon Country Contracting, Inc. | CP821 | Mine contractor | — |
| — | Canyon Rock Co., Inc. | CC6656 | Mine contractor | — |
| — | Canyon Rock Products LLC | CB5464 | Mine contractor | — |
| — | CAPCORP | CA230 | Mine contractor | — |
| — | Cape Special Road District | CF446 | Mine contractor | — |
| — | capital city group | CB1435 | Mine contractor | — |
| — | Capital City Machine Shop LLC | CC4478 | Mine contractor | — |
| — | Capital Electric Construction Company Inc., | CC2687 | Mine contractor | — |
| — | Capital Railroad Contracting Inc. | CB7538 | Mine contractor | — |
| — | Capital USA | CC6146 | Mine contractor | — |
| — | Capitol City Electric Inc. | CA9785 | Mine contractor | — |
| — | Capitol Rock Drilling & Blasting LLC | CA1641 | Mine contractor | — |
| — | Capling Leveling Inc. | CC9868 | Mine contractor | — |
| — | Capps Welding LLC | CC4419 | Mine contractor | — |
| — | Capra Group, Inc. | CB8475 | Mine contractor | — |
| — | CAPRIATI CONSTRUCTION CORP INC | CC9268 | Mine contractor | — |
| — | CAPT Services LLC | CC0020 | Mine contractor | — |
| — | Capurro Trucking | CF734 | Mine contractor | — |
| — | Carbon Direct LP | CA7171 | Mine contractor | — |
| — | Carbonet Nanotechnologies US Inc. | CC8362 | Mine contractor | — |
| — | Carew Concrete & Supply Co. | CA3602 | Mine contractor | — |
| — | Caribbean Construction Inc. | CG016 | Mine contractor | — |
| — | Carl's Dragline Service | CK439 | Mine contractor | — |
| — | Carlin Trend Mining Services | C8CI | Mine contractor | — |
| — | Carlisle Contracting LLC | CB7969 | Mine contractor | — |
| — | Carlton Group Inc. dba Carlton Scale | CP132 | Mine contractor | — |
| — | Carnegie Strategic Design Engineers | CY977 | Mine contractor | — |
| — | Carolina 1926 LLC | CFBY | Mine contractor | — |
| — | Carolina Aggregates and Sand Holdings LLC | CC8729 | Mine contractor | — |
| — | Carolina Chillers LLC | CC5395 | Mine contractor | — |
| — | Carolina Contracting Solutions | CE057 | Mine contractor | — |
| — | Carolina Drilling & Blasting | CH0F | Mine contractor | — |
| — | Carolina Elec Indus Maintenanc | CA341 | Mine contractor | — |
| — | Carolina Metal Solutions | CC5263 | Mine contractor | — |
| — | Carolina Scales Inc | CJVZ | Mine contractor | — |
| — | Carolina Vulcanizing Company | CC7987 | Mine contractor | — |
| — | Carothers Structural Concrete, Inc. | CC7457 | Mine contractor | — |
| — | Carpenter Excavating Inc | CB2270 | Mine contractor | — |
| — | Carr Electrical Technology Inc. | CB8381 | Mine contractor | — |
| — | Carrier Commercial Service | CU831 | Mine contractor | — |
| — | Carroll Service Company | CW905 | Mine contractor | — |
| — | CARROLL'S CONSTRUCTION | CX495 | Mine contractor | — |
| — | Carson Pump | CWLK | Mine contractor | — |
| — | Carter Dredging Company Inc. | CL915 | Mine contractor | — |
| — | Carter Machinery Co Inc | CBZ5 | Mine contractor | — |
| — | Carter Trucking | CTPC | Mine contractor | — |
| — | Carter Trucking LLC | CC3648 | Mine contractor | — |
| — | Cartey Electric Motors | CY145 | Mine contractor | — |
| — | Carver Sand & Gravel LLC | CA8300 | Mine contractor | — |
| — | CarWil LLC | CD214 | Mine contractor | — |
| — | Cary Specialized Services, Inc. | CA1447 | Mine contractor | — |
| — | Cascade Drilling LP | CWW8 | Mine contractor | — |
| — | Casella Construction Inc | CTGN | Mine contractor | — |
| — | Cash Metals & Recycling | CB1490 | Mine contractor | — |
| — | Cash Waggner & Associates, PC | CY811 | Mine contractor | — |
| — | Caster Enterprises | CC4608 | Mine contractor | — |
| — | CAT Welding & Maintenance Inc. | CB2137 | Mine contractor | — |
| — | Cate Equipment Company Inc | CK9Y | Mine contractor | — |
| — | Caterpillar, Inc. | C7YR | Mine contractor | — |
| — | CATFISH MOBILE WELDING | CA8502 | Mine contractor | — |
| — | Caudill Seed | CA2921 | Mine contractor | — |
| — | Cawvey's Electric Motor Service, Inc. | CH177 | Mine contractor | — |
| — | CAZ Trucking LLC | CX765 | Mine contractor | — |
| — | CB Group LLC | CC2041 | Mine contractor | — |
| — | CB Mining, Inc. | CA8539 | Mine contractor | — |
| — | Cb Trucking Inc | CB004 | Mine contractor | — |
| — | Cbc Engineers & Assoc | CWFF | Mine contractor | — |
| — | Cbec Inc | C6VU | Mine contractor | — |
| — | CBRE | CC7618 | Mine contractor | — |
| — | CC CALHOUN | CB2249 | Mine contractor | — |
| — | CCC Group Inc | CB96 | Mine contractor | — |
| — | Cci Mechanical Inc | CY92 | Mine contractor | — |
| — | CDE Global Inc | CB6504 | Mine contractor | — |
| — | CDL Electric Company Inc | CB7944 | Mine contractor | — |
| — | CDM Smith | CR230 | Mine contractor | — |
| — | CDP Consulting LLC | CC5179 | Mine contractor | — |
| — | CDR Industrial Maintenance | CC5727 | Mine contractor | — |
| — | CEDA Inc. | CC9942 | Mine contractor | — |
| — | Cedar Hill Landscaping | CA2473 | Mine contractor | — |
| — | CEM Service Group, Inc. | CY034 | Mine contractor | — |
| — | Cement Treated Base, LLC | CA8981 | Mine contractor | — |
| — | Cementation USA Inc. | CM445 | Mine contractor | — |
| — | Cemex Construction Materials South | CB2403 | Mine contractor | — |
| — | CEMSTONE PRODUCTS COMPANY | CG439 | Mine contractor | — |
| — | Cemtek Environmental | CA5583 | Mine contractor | — |
| — | Cemtek Systems, Inc. | CB0651 | Mine contractor | — |
| — | Centennial Concrete | CA5183 | Mine contractor | — |
| — | Centerstate Industrial services | CC6280 | Mine contractor | — |
| — | Centimark Corp | C1RD | Mine contractor | — |
| — | Central Contractors Supply Co | CXA8 | Mine contractor | — |
| — | Central Illinois Scale Company | CG060 | Mine contractor | — |
| — | Central Maintenance & Welding | CBL9 | Mine contractor | — |
| — | Central Nevada AC-DC Electric Inc. | CA9187 | Mine contractor | — |
| — | Central Pipe Rehab LLC. | CC2940 | Mine contractor | — |
| — | CENTRAL SERVICE & SUPPLY, INC. | CR944 | Mine contractor | — |
| — | Central Valley Mechanical General Engineering Inc. | CB3372 | Mine contractor | — |
| — | Centre Concrete Company | CB1202 | Mine contractor | — |
| — | Centrifugal & Mech Industries | CDJM | Mine contractor | — |
| — | Centrifugal Services Inc | CFPU | Mine contractor | — |
| — | Centurion Development Group | CC6974 | Mine contractor | — |
| — | Centurion Industries Inc | CM964 | Mine contractor | — |
| — | Century Blasting Service | CS287 | Mine contractor | — |
| — | Certerra Southwest, LLC | CA0381 | Mine contractor | — |
| — | Certified Seal Power Sweeping | CY415 | Mine contractor | — |
| — | Certified Sheet Metal | C1FA | Mine contractor | — |
| — | Cesar Velazquez Portable Welding | CC5764 | Mine contractor | — |
| — | Cetti Services Unlimited, Inc. | CY338 | Mine contractor | — |
| — | CFI CONSTRUCTION, INC. | CD0211 | Mine contractor | — |
| — | CGI Inc. Technologies and Solutions, Inc. | CC6498 | Mine contractor | — |
| — | Champagne & Marx Excavating Inc. | CB0083 | Mine contractor | — |
| — | Champion Charter Sales and Service | CT100 | Mine contractor | — |
| — | Champion Scale | CA2949 | Mine contractor | — |
| — | Champion Technology Services | CB0045 | Mine contractor | — |
| — | Chandler Aggregates | CC7920 | Mine contractor | — |
| — | Chaparral Chemical Company Inc | CA7301 | Mine contractor | — |
| — | Chapman Electrical Contracting | CA497 | Mine contractor | — |
| — | Chapman Welding, LLC | CB7946 | Mine contractor | — |
| — | Charah LLC | CA3421 | Mine contractor | — |
| — | Charles H. Hamilton Company | CHE9 | Mine contractor | — |
| — | CHARLIE C., INC | CA7195 | Mine contractor | — |
| — | Charlie's Welding Services | CB8856 | Mine contractor | — |
| — | Charlotte Scale Co Inc | C9RT | Mine contractor | — |
| — | Charlson Excavating Co Of Clea | CLAR | Mine contractor | — |
| — | Chase's Towing Limestone Division, LLC | CC0312 | Mine contractor | — |
| — | Chase's Towing, LLC | CA8185 | Mine contractor | — |
| — | Check-6, Inc. | CA5200 | Mine contractor | — |
| — | Chem Treat Inc | C3UG | Mine contractor | — |
| — | Chemco Products | CA4893 | Mine contractor | — |
| — | Chemistry & Industrial Hygiene, Inc. | CA3047 | Mine contractor | — |
| — | Chemstream, Inc. | CS493 | Mine contractor | — |
| — | Chemung Contracting Corp | C9SF | Mine contractor | — |
| — | CHERENZIA EXCAVATION | CW919 | Mine contractor | — |
| — | Cherokee Chemical Co Inc | C6NB | Mine contractor | — |
| — | Cherokee Equipment Inc | CB104 | Mine contractor | — |
| — | Cherry County | CF363 | Mine contractor | — |
| — | Chesapeake Containment Systems | CC1122 | Mine contractor | — |
| — | Chewning & Wilmer, Inc. | CP285 | Mine contractor | — |
| — | Childs Geoscience Inc. | CA6935 | Mine contractor | — |
| — | Chilton's Industrial Machine & Tool Co., Inc. | CJ886 | Mine contractor | — |
| — | Chippewa Concrete Services, Inc. | CA6566 | Mine contractor | — |
| — | Chisler Brothers | CC66 | Mine contractor | — |
| — | Chisler Inc | CPSK | Mine contractor | — |
| — | Chism concrete construction | CC3329 | Mine contractor | — |
| — | Chris Amschler Tree Service & Landscaping | CC6001 | Mine contractor | — |
| — | Chris Charles Trucking, Inc. | CD861 | Mine contractor | — |
| — | Chris Shipley Excavating, LLC | CA6383 | Mine contractor | — |
| — | Christensen Brothers Asphalt, LLC | CC3256 | Mine contractor | — |
| — | CHS Industrial Inc. | CS966 | Mine contractor | — |
| — | CIRCULAR USA INC | CC5430 | Mine contractor | — |
| — | Cisco Air Systems Inc | CA1061 | Mine contractor | — |
| — | Citizens Electric Corp | CYBM | Mine contractor | — |
| — | Citrine Welding Solutions | CC8809 | Mine contractor | — |
| — | City Of Asheboro | CB221 | Mine contractor | — |
| — | City of Columbus - Parsons Avenue Water Plant | CC9490 | Mine contractor | — |
| — | Civil LLC | CB7523 | Mine contractor | — |
| — | CJ LUSK | CC6155 | Mine contractor | — |
| — | CJC Painting, inc. | CC0521 | Mine contractor | — |
| — | CKG Services LLC | CC9108 | Mine contractor | — |
| — | Claiborne Hauling LLC | CU326 | Mine contractor | — |
| — | Clairemont Equipment Rentals & Sales Service | CP164 | Mine contractor | — |
| — | Clariant Corporation | CA7426 | Mine contractor | — |
| — | CLARK LABORATORIES, LLC. | CN005 | Mine contractor | — |
| — | Clark's Commercial Services, LLC | CB2640 | Mine contractor | — |
| — | Clark's Welding, LLC | CC4579 | Mine contractor | — |
| — | CLARKS FIELD SERVICE LLC | CC5976 | Mine contractor | — |
| — | Classic Industrial Services, Inc. | CH476 | Mine contractor | — |
| — | Classic Trucking | CT890 | Mine contractor | — |
| — | Claude V Keen Trucking Co | CIVG | Mine contractor | — |
| — | Claudius Peters (Americas) | CT316 | Mine contractor | — |
| — | Clay Trucking, Inc. | CG448 | Mine contractor | — |
| — | Claystone Construction, LLC | CG840 | Mine contractor | — |
| — | Clayton Industries | CU546 | Mine contractor | — |
| — | Clean Away Parking Lot Cleaning | CC6798 | Mine contractor | — |
| — | Clean Harbors Environmental Services Inc. | CRUZ | Mine contractor | — |
| — | Clean Water Service, Inc. | CP517 | Mine contractor | — |
| — | Clear Creek Associates | CC125 | Mine contractor | — |
| — | Clear Cut Tree Company | CC9529 | Mine contractor | — |
| — | Clear Development, LLC | CR505 | Mine contractor | — |
| — | Clear View Builders | CC3666 | Mine contractor | — |
| — | Clear Water Services | CC7986 | Mine contractor | — |
| — | CLEARENERGY.LLC | CA9046 | Mine contractor | — |
| — | Clemmer's Construction Co., LLC | CH354 | Mine contractor | — |
| — | Cleveland Brothers Equipment | CU2X | Mine contractor | — |
| — | CLEVELAND ELECTRIC | CG770 | Mine contractor | — |
| — | ClimalockLLC | CB1184 | Mine contractor | — |
| — | Climate Engineers | CV177 | Mine contractor | — |
| — | Clinch Co Inc | CC9653 | Mine contractor | — |
| — | Clinch Mountain Transport Inc | CXYM | Mine contractor | — |
| — | Clinton'S Welding | CA044 | Mine contractor | — |
| — | CLSI, Inc. | CA1776 | Mine contractor | — |
| — | CMC Tire | CB1409 | Mine contractor | — |
| — | CMT LABS | CA6160 | Mine contractor | — |
| — | CNR | CB6825 | Mine contractor | — |
| — | CNY stone | CC5961 | Mine contractor | — |
| — | Co-op Industries, Inc. | CA2470 | Mine contractor | — |
| — | Coach U.S.A. | C9VD | Mine contractor | — |
| — | Coal Field Construction Company LLC | CW314 | Mine contractor | — |
| — | Coal-Mac LLC | CC3141 | Mine contractor | — |
| — | Coalfield Services, Inc | CR58 | Mine contractor | — |
| — | Coalmont Electric Dev. Co. | CG366 | Mine contractor | — |
| — | Coastal Asphalt LLC | CC9968 | Mine contractor | — |
| — | Coastal Dredging | CB9803 | Mine contractor | — |
| — | Coastal Dredging Company, Inc | CC5276 | Mine contractor | — |
| — | Coastal Equipment Corporation | CB2104 | Mine contractor | — |
| — | Coastal Group | CC5570 | Mine contractor | — |
| — | Coastal Process, LLC | CD0271 | Mine contractor | — |
| — | Coastal Well Service, LLC | CC2526 | Mine contractor | — |
| — | Coastline Equipment | CE089 | Mine contractor | — |
| — | Cobb Site Development, Inc. | CU749 | Mine contractor | — |
| — | Cobra Equipment Repair | CC3931 | Mine contractor | — |
| — | Cockburn Enterprises | CC7379 | Mine contractor | — |
| — | Coffey County Road & Bridge Dept. | CN626 | Mine contractor | — |
| — | Coffin'S Gravel & Excavating | CA121 | Mine contractor | — |
| — | Coffman Engineers, Inc. | CC9500 | Mine contractor | — |
| — | Cogar Manufacturing, Inc. | CYPY | Mine contractor | — |
| — | Cogburn Bros., Inc. | CA2774 | Mine contractor | — |
| — | COI Crane Service | CB8175 | Mine contractor | — |
| — | Colaska Inc dba Secon | CM905 | Mine contractor | — |
| — | Cold Creek Nurseries | CB2033 | Mine contractor | — |
| — | Cold Spring Construction Co | CA2940 | Mine contractor | — |
| — | Cold Spring Electric | CC9306 | Mine contractor | — |
| — | Cole & Headley Enterprises | CC9053 | Mine contractor | — |
| — | Cole Oil Co. Inc. | CM450 | Mine contractor | — |
| — | Coleman Electrical Services, LLC | CX935 | Mine contractor | — |
| — | Coleman Engineering Company | CA2747 | Mine contractor | — |
| — | Coleman Trucking Inc | CP6F | Mine contractor | — |
| — | Colgate Drilling LLC | CC3383 | Mine contractor | — |
| — | Collier Geophysics, LLC | CC5377 | Mine contractor | — |
| — | Collier Welding and More LLC | CC7364 | Mine contractor | — |
| — | Colliers Engineering and Design | CB4099 | Mine contractor | — |
| — | Collins Communications Inc | CYDJ | Mine contractor | — |
| — | Collins Electric | CMRF | Mine contractor | — |
| — | COLLINS ELECTRIC CO INC | CP397 | Mine contractor | — |
| — | Collins Welding and Fabrication | CB5123 | Mine contractor | — |
| — | Colony Tire Corp | CB464 | Mine contractor | — |
| — | Colorado Lien Company | CH4P | Mine contractor | — |
| — | Colorado Lining Co | CSAS | Mine contractor | — |
| — | Colstrip Electric Inc | CEFG | Mine contractor | — |
| — | Colt Rock and Lime LLC | CC9477 | Mine contractor | — |
| — | Colt45 maintenance Solutions,llc | CC8915 | Mine contractor | — |
| — | COLUMBIA RUBBER CORPORATION | CS340 | Mine contractor | — |
| — | Columbus Equipment Company | CD136 | Mine contractor | — |
| — | Comal Emissions Testing, LLC | CC2969 | Mine contractor | — |
| — | Comanco Environmental Corp | CF350 | Mine contractor | — |
| — | Comer Electric Co. | CD0263 | Mine contractor | — |
| — | Comfort Systems USA (AR), Inc. | CMBW | Mine contractor | — |
| — | Comfort Systems USA Southwest | CX775 | Mine contractor | — |
| — | Comfort Zone Heating & Cooling LLC | CA4472 | Mine contractor | — |
| — | Commander Industrial, Inc. | CA1554 | Mine contractor | — |
| — | Commerce Coating Services | CC7407 | Mine contractor | — |
| — | Commercial & Residential Sanitation | CB1738 | Mine contractor | — |
| — | Commercial Air and Electric Inc. | CS223 | Mine contractor | — |
| — | Commercial Services Unlimited Inc | CC1528 | Mine contractor | — |
| — | Commercial Steel Erection Inc | CDIC | Mine contractor | — |
| — | Commercial Tire | CH976 | Mine contractor | — |
| — | Commercial Tire Service | CB0331 | Mine contractor | — |
| — | Commonwealth Electric Company of the Midwest | CA1158 | Mine contractor | — |
| — | Commonwealth Equipment Corporation | CD656 | Mine contractor | — |
| — | Commonwealth Railway, Inc | CC5662 | Mine contractor | — |
| — | Communication Technologies, Inc. | CF175 | Mine contractor | — |
| — | Communications Technology II, LLC | CA2608 | Mine contractor | — |
| — | Community Fire Extinguisher Inc. | CA9593 | Mine contractor | — |
| — | Company Owned Operations/Div of BATO | CJHR | Mine contractor | — |
| — | Company Wrench | CR825 | Mine contractor | — |
| — | Complete Control, Inc | CLUM | Mine contractor | — |
| — | Complete Fire Protection, LLC | CQ173 | Mine contractor | — |
| — | Complete General Construction Company | CA1224 | Mine contractor | — |
| — | Complete Mechanical Contracting Inc | CA4348 | Mine contractor | — |
| — | Complete Quarry Services LLC | CB3639 | Mine contractor | — |
| — | Compliance Monitoring Labs Inc | CRIU | Mine contractor | — |
| — | Compliance Staffing Agency LLC DBA Jennmar Service | CA5566 | Mine contractor | — |
| — | Compressed Air Consultants | CP838 | Mine contractor | — |
| — | Compressed Air Solutions, LLC | CA3444 | Mine contractor | — |