Which US coal mine has the highest silica content in its MSHA dust samples?

US coal mines with the most silica in their dust samples

Respirable-dust samples at Toney Fork Surface Mine carry the highest average crystalline silica content of any US coal mine in MSHA records, at 26.2% quartz across 36 samples. Next are Patriot Mining Company Inc (24.8%) and Bent Mountain Surface Mine #2 (21.1%).

US coal mines ranked by the average crystalline silica (quartz) content of their MSHA respirable-dust samples, the fraction the 2024 federal silica rule targets. Click a mine for its full sampling and compliance record.

This is the silica share of the respirable dust that was sampled, averaged over the mine's records. It reflects the geology of the material and dust control, and is a point-in-time sampling measurement, not a personal exposure dose or a compliance judgment. Only mines with at least 30 quartz samples on record are ranked, so a stray reading cannot drive the average.

Looking at enforcement instead? See mines ranked by imminent-danger orders or by MSHA violations. For emissions, see coal mines ranked by reported methane. For hearing damage, see mines ranked by noise samples over the legal limit.

Top 100 by average respirable silica Average quartz percent across each mine's samples

01 Toney Fork Surface Mine Coal Mac East · WV 26.2% avg silica max 55.1% · 36 samples
02 Patriot Mining Company Inc Patriot Mining Company LLC · WV 24.8% avg silica max 47.7% · 44 samples
03 Bent Mountain Surface Mine #2 FR Performance LLC · KY 21.1% avg silica max 50.2% · 47 samples
04 Holden #22 Surface Coal-Mac LLC · WV 19.9% avg silica max 47.5% · 40 samples
05 Virginia Point No. 1 Surface Mine Extra Energy, Inc. · VA 19.7% avg silica max 40.0% · 41 samples
06 Black Castle Mining Company, LLC Black Castle Mining Company, LLC · WV 19.2% avg silica max 50.6% · 37 samples
07 Twilight Mtr Surface Mine Lexington Coal Company, LLC · WV 19.0% avg silica max 52.9% · 47 samples
08 Job #49 Reckoning Reclamation,LLC. · KY 18.1% avg silica max 40.4% · 44 samples
09 Broad Run Mine Big River Mining LLC · WV 17.9% avg silica max 44.5% · 33 samples
10 Sycamore Surface Mine Panther Creek Mining LLC · WV 17.8% avg silica max 46.5% · 30 samples
11 Samples Surface Mine Panther Creek Mining LLC · WV 17.7% avg silica max 49.3% · 99 samples
12 Wilson Strip #6 Buffalo Coal Company Inc · WV 17.7% avg silica max 56.3% · 44 samples
13 Laurel Branch Surface Clintwood JOD, LLC · VA 17.6% avg silica max 45.3% · 61 samples
14 Ewing Fork No. 1 Surface Mine Republic Energy LLC · WV 17.5% avg silica max 36.7% · 42 samples
15 88 Strip Paramont Contura, LLC · VA 17.1% avg silica max 49.0% · 125 samples
16 Speedway No 1 Strip Mine Sky Haven Coal Inc · PA 17.1% avg silica max 59.4% · 56 samples
17 Waroquier #1 Waroquier Coal, Inc. · PA 16.9% avg silica max 40.5% · 36 samples
18 Frasure Creek Mine No 6 Frasure Creek Mining, LLC. · KY 16.8% avg silica max 47.4% · 64 samples
19 Fishtrap Highland Energy, Inc. · AL 16.7% avg silica max 33.0% · 51 samples
20 Mine No 1 PBS Coals, Inc. · PA 16.5% avg silica max 53.8% · 40 samples
21 Manchester Mine Black Warrior Minerals Inc · AL 16.5% avg silica max 53.1% · 41 samples
22 Republic Energy Republic Energy LLC · WV 16.2% avg silica max 41.1% · 62 samples
23 Workman Creek Surface Republic Energy LLC · WV 15.9% avg silica max 32.5% · 119 samples
24 JoePa Rosebud Mining Company · PA 15.7% avg silica max 44.8% · 32 samples
25 Orange Strip B & N Coal Inc · OH 15.4% avg silica max 42.1% · 101 samples
26 Dry Branch Surface Mine Extra Energy, Inc. · WV 15.4% avg silica max 33.9% · 53 samples
27 Black Knight II Elk Run Coal Company, LLC · WV 15.3% avg silica max 31.7% · 55 samples
28 Sloan Mountain Mine Iron Eagle Land Rehabilitation, LLC · AL 15.1% avg silica max 27.8% · 57 samples
29 Searles Mine No. 2, 3, 4, 5, 6, 7, 8 & 9 Southland Resources, Inc. · AL 15.1% avg silica max 35.6% · 47 samples
30 Continental Strip Keystone Anthracite Corporation · PA 14.4% avg silica max 44.6% · 38 samples
31 GRAPEVINE SOUTH SURFACE MINE APPALACHIAN RESOURCE WEST VIRGINIA, LLC · WV 14.3% avg silica max 40.1% · 55 samples
32 Low Gap Powellton #1 Mine Marfork Coal Company Inc · WV 14.2% avg silica max 39.9% · 38 samples
33 Eckman Surface Mine Extra Energy, Inc. · WV 14.0% avg silica max 41.9% · 65 samples
34 Three Mile Mine #1 CAM Mining LLC · KY 14.0% avg silica max 45.6% · 33 samples
35 Mine No. 1 Onyx Energy, LLC · WV 13.7% avg silica max 40.6% · 52 samples
36 Black Warrior Mine No 1 Black Warrior Minerals, Inc. · AL 13.7% avg silica max 27.9% · 86 samples
37 Colowyo Mine Kiewit Mining Group Inc · CO 13.5% avg silica max 56.3% · 57 samples
38 East Mac & Nellie Pine Branch Mining LLC · KY 13.4% avg silica max 45.9% · 58 samples
39 Stockburg No 2 Remington LLC · WV 13.2% avg silica max 42.6% · 36 samples
40 Feller #2 Strip Cooney Bros Coal Co · PA 13.2% avg silica max 47.4% · 49 samples
41 Remining #3 Appalachian Resource West Virginia, LLC · WV 13.1% avg silica max 41.1% · 54 samples
42 Shannon Mine No. 3 RJR Mining Company, Inc. · AL 13.0% avg silica max 23.8% · 39 samples
43 Mine #30 R & R Mining, Inc. · KY 13.0% avg silica max 21.7% · 62 samples
44 EPB Strip E P Bender Coal Company · PA 12.9% avg silica max 29.7% · 30 samples
45 Combs Branch Job Pine Branch Mining LLC · KY 12.9% avg silica max 48.6% · 38 samples
46 Coalburg Tunnel Mine Kanawha Eagle Mining, LLC · WV 12.9% avg silica max 42.1% · 54 samples
47 White Queen Marfork Coal Company Inc · WV 12.6% avg silica max 33.7% · 63 samples
48 Thunder Ridge Pine Branch Mining LLC · KY 12.4% avg silica max 60.3% · 51 samples
49 Deep Mine # 6 Paramont Coal Company Virginia, LLC · VA 12.4% avg silica max 31.3% · 69 samples
50 Boone North No. 2 Surface Mine Eagle Horizon Resources, LLC · WV 12.4% avg silica max 45.7% · 30 samples
51 CABIN RUN 97 Mining Holding Company, LLC · MD 12.3% avg silica max 53.5% · 45 samples
52 Jap Creek Mine Mays Mining, Inc. · AL 12.3% avg silica max 26.6% · 33 samples
53 Rowdy Gap Mine Pine Branch Mining LLC · KY 12.3% avg silica max 42.1% · 39 samples
54 Choctaw Mine Iron Eagle Land Rehabilitation, LLC · AL 12.3% avg silica max 35.2% · 63 samples
55 WAR CREEK NO. 1 Black River Coal, LLC · VA 12.2% avg silica max 29.0% · 35 samples
56 Glancy Surface Mine Rockwell Mining LLC · WV 12.0% avg silica max 41.0% · 50 samples
57 #20 Strip Job Pine Branch Mining LLC · KY 12.0% avg silica max 50.3% · 48 samples
58 Eagle Mine Jet Coal Company Incorporated · KY 11.9% avg silica max 24.1% · 81 samples
59 Le-Ib Mine Blair Coal Company Inc · KY 11.9% avg silica max 42.2% · 44 samples
60 Logan Surface Mine Blaschak Anthracite Corporation · PA 11.9% avg silica max 40.6% · 52 samples
61 Black King I North Portal Elk Run Coal Company Inc · WV 11.7% avg silica max 32.3% · 203 samples
62 Ky No. Mine 1 Middle Fork Mining, Inc. · KY 11.7% avg silica max 28.2% · 37 samples
63 Big Mountain No 16 Pine Ridge Coal Company LLC · WV 11.5% avg silica max 40.4% · 170 samples
64 Mine #1 Clean Energy Mining Co. · KY 11.5% avg silica max 34.7% · 155 samples
65 Horizon Mine Hidden Splendor Resources Inc · UT 11.5% avg silica max 38.0% · 63 samples
66 Deep Mine 37 Paramont Contura, LLC · VA 11.4% avg silica max 36.6% · 84 samples
67 Jim Bridger Mine Bridger Coal Company · WY 11.3% avg silica max 16.6% · 38 samples
68 No 12 North Star Mining, Inc. · KY 11.3% avg silica max 24.8% · 45 samples
69 Coalburg No 2 Mine Rio Group, Inc. · WV 11.3% avg silica max 34.1% · 31 samples
70 Genesis No. 17 Genesis Inc · PA 11.2% avg silica max 40.6% · 100 samples
71 Mine No. 1 Triple G Coal Company, Inc · WV 11.1% avg silica max 45.2% · 33 samples
72 River Hill Coal Co., Inc. River Hill Coal Company Inc · PA 11.0% avg silica max 44.5% · 40 samples
73 Mine #23 CAM Mining LLC · KY 11.0% avg silica max 30.1% · 83 samples
74 Eagle No. 1 Mine Mega Highwall Mining, LLC · WV 10.9% avg silica max 32.0% · 52 samples
75 Miller Mine RoxCoal Inc · PA 10.8% avg silica max 32.5% · 104 samples
76 No 8 Mine Patton Inc · WV 10.8% avg silica max 19.6% · 33 samples
77 Jims Branch No 2 Chief Mining Inc · WV 10.8% avg silica max 36.4% · 56 samples
78 Hawkeye Mine Knight Hawk Coal, LLC · IL 10.8% avg silica max 29.8% · 43 samples
79 Lindbergh Centennial Natural Resources, LLC · AL 10.8% avg silica max 26.4% · 33 samples
80 TWIN BRANCH NO 1 SURFACE COAL-MAC LLC. · WV 10.7% avg silica max 34.5% · 45 samples
81 Buffalo Deep Mine Hampden Coal LLC · WV 10.6% avg silica max 21.6% · 66 samples
82 Lee Ranch Coal Mine Peabody Natural Resources Company · NM 10.6% avg silica max 20.9% · 38 samples
83 Mine No 9 Hubble Mining Company LLC · KY 10.6% avg silica max 24.8% · 53 samples
84 Mine No. 14 Premium Coal Company,Inc. · TN 10.6% avg silica max 27.4% · 41 samples
85 RES Morrisdale RES Coal LLC · PA 10.6% avg silica max 52.7% · 38 samples
86 3C A B & J Coal Co. Inc. · KY 10.6% avg silica max 25.5% · 39 samples
87 No 1 Linsco Energy LLC · KY 10.5% avg silica max 35.7% · 30 samples
88 Wildcat Hills Mine - Cottage Grove Pit Peabody Midwest Mining, LLC · IL 10.5% avg silica max 32.8% · 63 samples
89 Black Butte And Leucite Hills Mines Black Butte Coal Company · WY 10.5% avg silica max 20.5% · 61 samples
90 RES Houtzdale RES Coal LLC · PA 10.3% avg silica max 43.1% · 35 samples
91 No 57 Mine Nufac Mining Company, Inc · WV 10.3% avg silica max 29.5% · 48 samples
92 Thompson Mine No 1 Tacoa Minerals, LLC · AL 10.3% avg silica max 19.1% · 36 samples
93 Right Fork Splint 101 Coal, Inc. · KY 10.3% avg silica max 56.2% · 46 samples
94 No 2 Panzer Coal Inc · KY 10.2% avg silica max 29.7% · 94 samples
95 Narley Mine Iron Eagle Land Rehabilitation, LLC · AL 10.2% avg silica max 20.5% · 36 samples
96 No 4 East Star Mining Inc · VA 10.2% avg silica max 22.0% · 39 samples
97 Winifrede No. 13-A Mine Rockwell Mining, LLC. · WV 10.2% avg silica max 23.9% · 34 samples
98 Rossmoyne No. 1 Mine Rosebud Mining Company · PA 10.1% avg silica max 36.5% · 77 samples
99 Mine No 4 North Fork Coal Corporation · KY 10.1% avg silica max 34.3% · 122 samples
100 R F #3 Elkhorn CAM Mining LLC · KY 10.1% avg silica max 24.2% · 58 samples