Thunder Mountain Quarry has $13K in proposed MSHA penalties and $151 outstanding across 2 contested dockets, plus health sampling and the full incident record.
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Fatalities
0
Total incidents
10
Years on record
1995–2022
Latest incident
Jan 2022
Compliance record
MSHA citations since 2000
95
citations
20
significant & substantial
$12,753
proposed penalties
$12,468
paid to date
98% of proposed penalties paid to date, a $285 gap.
citations per 100 inspection hours
ⓘThis rate is recorded citations divided by MSHA inspection hours, per 100 hours. It reflects inspection effort, not mine size or production.
Rate withheld: 822 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Thunder Mountain Quarry has $13K in proposed MSHA penalties and $151 outstanding across 2 contested dockets.
Penalty disposition
ⓘDifferences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.
$13K
proposed penalties
$13K
current assessed
$12K
paid to date
$151
outstanding
95 assessments are final orders; 2 contested dockets.
Of $2K in penalties contested before the Commission, $2K was upheld in final decisions.
As of the most recent assessment on 2026-06-11.
Source: MSHA assessed-violations and conference/litigation data, updated weekly.
Violation severity profile
ⓘShares are computed over citations that carry the MSHA gravity and negligence coding; a small share of records are uncoded.
Source: MSHA violations gravity and negligence coding, updated weekly.
Contested penalties
ⓘA reduction or dismissal at the Commission is a lawful outcome of contesting a proposed penalty. Figures are the proposed amount and the amount upheld in the docket's decision.
Largest penalties this mine contested before the Federal Mine Safety and Health Review Commission, with the outcome on record.
Health sampling
ⓘA sample is a point in time compliance measurement, not an individual exposure history. These figures describe MSHA sampling records and do not establish causation or personal dose.
Metal and nonmetal contaminants (personal samples)
ⓘMany samples are screening measurements of substances with no applicable exposure limit; they are counted as samples but excluded from every over-limit figure. Over-limit shares use only limit-tested samples.
Last sampled: 2022-09-15, 3 years ago
7
samples
0
limit-tested
Most sampled contaminants
Unlisted Particulate, respirable, <1% Qtz4
Respirable dust, <.1mg3
Show the individual readings (7)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2022-09-15
Unlisted Particulate, respirable, <1% Qtz
0.24
Backhoe Operator
2022-09-15
Unlisted Particulate, respirable, <1% Qtz
0.2
Front-end Loader Operator
2017-08-22
Unlisted Particulate, respirable, <1% Qtz
0.33
Backhoe Operator
2010-01-26
Respirable dust, <.1mg
0
Front-end Loader Operator
2002-08-29
Unlisted Particulate, respirable, <1% Qtz
0.13
Backhoe Operator
2002-08-29
Respirable dust, <.1mg
0
Truck Driver
2002-08-29
Respirable dust, <.1mg
0
Front-end Loader Operator
Source: MSHA respirable dust, quartz, and noise sampling records, updated weekly. Metal/nonmetal contaminant figures come from MSHA's Personal Health Samples and Area Samples files (public record), updated weekly.
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year
Employees
2026
3
2025
3
2024
3
2023
3
2022
3
2021
3
2020
3
2019
3
2018
3
2017
3
2016
2
2014
1
2013
4
2012
6
2011
6
2010
6
2009
6
2008
8
2007
8
2006
8
2005
8
2004
7
2003
7
2002
7
2001
7
2000
8
Source: MSHA quarterly employment and production, updated weekly.
Thunder Mountain Quarry sits in King County, Washington, where the Census mining category is 0.0% of county employment.
Local economic context
ⓘCounty figures come from the US Census Bureau's American Community Survey, 5-year pooled estimates, so the 2023 vintage covers 2019 through 2023. The Census category is 'mining, quarrying, and oil and gas extraction', which is broader than MSHA jurisdiction and includes oil and gas workers no mine employs. These figures describe the surrounding county, not this mine, and are not a factor in any specific incident.
King County, Washington · Population 2,262,713
0.0%
Mining share of county employment
$122,148
Median household income
Source: US Census Bureau, American Community Survey 2023 5-year estimates.
Quarterly safety rates
ⓘCitations per million reported employee-hours. Rates begin in 2000, when MSHA's quarterly employment data starts; earlier incidents are counted but cannot be rate-adjusted. Quarters under 100,000 reported hours are greyed: too few hours for a stable rate.
Citations per million employee-hours, as reported to MSHA
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2026 Q2
1,600
1
0
625.0
2026 Q1
1,508
0
0
0.0
2025 Q4
1,561
1
1
640.6
2025 Q3
1,496
1
1
668.4
2025 Q2
1,527
0
0
0.0
2025 Q1
1,463
2
0
1367.1
2024 Q4
1,577
0
0
0.0
2024 Q3
1,601
0
0
0.0
Show 90 earlier quartersHide earlier quarters
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2024 Q2
1,601
3
2
1873.8
2024 Q1
1,508
3
0
1989.4
2023 Q4
1,493
0
0
0.0
2023 Q3
1,457
0
0
0.0
2023 Q2
1,644
1
0
608.3
2023 Q1
1,473
0
0
0.0
2022 Q4
1,367
0
0
0.0
2022 Q3
1,740
0
0
0.0
2022 Q2
1,713
0
0
0.0
2022 Q1
1,344
7
0
5208.3
2021 Q4
1,715
0
0
0.0
2021 Q3
1,660
0
0
0.0
2021 Q2
1,208
1
1
827.8
2021 Q1
1,581
2
0
1265.0
2020 Q4
1,607
0
0
0.0
2020 Q3
1,454
2
0
1375.5
2020 Q2
1,518
0
0
0.0
2020 Q1
1,622
3
0
1849.6
2019 Q4
1,582
0
0
0.0
2019 Q3
1,630
0
0
0.0
2019 Q2
1,527
4
1
2619.5
2019 Q1
1,686
0
0
0.0
2018 Q4
1,619
2
0
1235.3
2018 Q3
1,937
0
0
0.0
2018 Q2
1,536
0
0
0.0
2018 Q1
1,491
0
0
0.0
2017 Q4
1,577
2
0
1268.2
2017 Q3
1,642
0
0
0.0
2017 Q2
1,538
0
0
0.0
2017 Q1
1,343
0
0
0.0
2016 Q4
80
0
0
0.0
2014 Q3
0
0
0
2014 Q2
40
0
0
0.0
2014 Q1
21
0
0
0.0
2013 Q4
62
0
0
0.0
2013 Q3
93
0
0
0.0
2013 Q2
1,097
1
0
911.6
2013 Q1
2,876
0
0
0.0
2012 Q4
2,806
0
0
0.0
2012 Q3
3,292
0
0
0.0
2012 Q2
815
0
0
0.0
2012 Q1
2,338
0
0
0.0
2011 Q4
2,864
0
0
0.0
2011 Q3
2,594
0
0
0.0
2011 Q2
2,543
0
0
0.0
2011 Q1
2,255
1
0
443.5
2010 Q4
2,282
0
0
0.0
2010 Q3
2,357
1
0
424.3
2010 Q2
2,328
0
0
0.0
2010 Q1
2,519
1
1
397.0
2009 Q4
2,524
0
0
0.0
2009 Q3
2,613
0
0
0.0
2009 Q2
2,180
0
0
0.0
2009 Q1
3,155
0
0
0.0
2008 Q4
3,301
0
0
0.0
2008 Q3
3,881
0
0
0.0
2008 Q2
3,804
3
2
788.6
2008 Q1
3,813
2
0
524.5
2007 Q4
3,960
0
0
0.0
2007 Q3
3,859
0
0
0.0
2007 Q2
3,804
0
0
0.0
2007 Q1
3,710
0
0
0.0
2006 Q4
4,195
2
1
476.8
2006 Q3
4,054
1
0
246.7
2006 Q2
4,020
0
0
0.0
2006 Q1
3,825
0
0
0.0
2005 Q4
3,963
0
0
0.0
2005 Q3
4,358
0
0
0.0
2005 Q2
4,068
1
0
245.8
2005 Q1
4,126
0
0
0.0
2004 Q4
3,869
2
0
516.9
2004 Q3
3,718
0
0
0.0
2004 Q2
3,691
0
0
0.0
2004 Q1
3,555
0
0
0.0
2003 Q4
3,391
4
0
1179.6
2003 Q3
3,329
0
0
0.0
2003 Q2
3,072
2
1
651.0
2003 Q1
3,196
2
1
625.8
2002 Q4
3,110
0
0
0.0
2002 Q3
3,439
1
0
290.8
2002 Q2
3,077
0
0
0.0
2002 Q1
2,818
0
0
0.0
2001 Q4
3,249
0
0
0.0
2001 Q3
3,361
3
0
892.6
2001 Q2
3,212
0
0
0.0
2001 Q1
3,037
0
0
0.0
2000 Q4
3,246
0
0
0.0
2000 Q3
2,800
0
0
0.0
2000 Q2
3,423
0
0
0.0
2000 Q1
3,083
31
7
10055.1
No fatalities recorded at this mine.
Reportable incidents
10 on file
2022 · 1 incident
January 20, 2022WA · Metal/Non-Metalfront-end loader, scraper-loader operator, pan operator, payloader, scraper rig operatorSLIP OR FALL OF PERSON
Cadman Inc. · Over-exertion (Not Elsewhere Classified)
After getting down from a loader, employee tripped over a rock in the mud and sustained injuries to EE's ankle.
2021 · 1 incident
April 14, 2021WA · Metal/Non-Metalweighman, scale personOTHER
Cadman Inc. · Absorption of radiations, caustics, toxic and noxious substances
While using the porta potty restroom employee stung on the right butt cheek due to bee being on toilet seat.
2010 · 1 incident
October 4, 2010WA · Metal/Non-Metalbulldozer operator, universal operator, heavy equipment operator, operating engineerMACHINERY
EE was mining with a Kobelco excavator in a very difficult area and was jolted by impact of machine to ground contact several times a day causing pain to his right hand, arm, shoulder and neck. Did not receive paperwork from Dr until Dec 1, 2010 for L&I
Track excavator tracked too close to edge of access ramp to working pad. Machine slid sideways 5' onto its side. Ramp and working pad with berms were over excavated. Minor injury to operator. Minimal damage to equipment.
2004 · 1 incident
July 30, 2004WA · Metal/Non-Metalbulldozer operator, universal operator, heavy equipment operator, operating engineerMACHINERY