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Yosemite Slate Quarry: 19 MSHA citations Metal/Non-Metal

Mariposa Yosemite Slate Quarry · Surface
Controlled by David R Butler
mariposa, Mariposa County, CA  ·  Intermittent
MSHA Mine ID: 0400357

Yosemite Slate Quarry has $3K in proposed MSHA penalties and $187 outstanding across 3 contested dockets, plus health sampling and the full incident record.

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Fatalities
0
Total incidents
1
Years on record
2006
Latest incident
Jan 2006
Compliance record
MSHA citations since 2001
19
citations
6
significant & substantial
$2,552
proposed penalties
$2,199
paid to date
86% of proposed penalties paid to date, a $353 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2000
52
inspections on record
516
inspection hours
n/a
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: 516 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.

Yosemite Slate Quarry has $3K in proposed MSHA penalties and $187 outstanding across 3 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.
$3K
proposed penalties
$2K
current assessed
$2K
paid to date
$187
outstanding
19 assessments are final orders; 3 contested dockets.
Of $555 in penalties contested before the Commission, $389 was upheld in final decisions.
As of the most recent assessment on 2024-06-25.
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.
31.6%
significant & substantial
5.3%
high negligence or reckless
31.6%
reasonably likely or greater
31.6%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 36.8% low, 57.9% moderate, 5.3% high, 0.0% reckless.
Source: MSHA violations gravity and negligence coding, updated weekly.
When citations were contested
ⓘ Contesting a citation before the Federal Mine Safety and Health Review Commission is a lawful right. These figures state the public outcomes of that process, from MSHA's Contested Violations file.
4 citations taken to the federal commission · 21% of citations on record
  • Settled 3 · 75%
  • Stood as issued 1 · 25%
100%
S&S designation survived the contest
ⓘ Counts a Significant & Substantial citation as surviving when a settlement or judge's decision kept the designation, or the contest was dismissed or defaulted so the citation stands as issued. Vacated and withdrawn citations, and settlements that removed the designation, count against.
of 3 decided S&S contests · industry: 79%
30%
Penalty reduction in decided contests
$555 proposed, $389 after decisions · industry: 39%
Source: MSHA Contested Violations file (public record), updated weekly. A dismissed or defaulted contest leaves the citation standing as issued; a vacated or withdrawn citation is removed from the violation record. Latest contest filed 2016-09-21.
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.
Docket Decision Judge Year Proposed / upheld
WEST 2013-740M Settlement Manning 2013 $243 → $100
WEST 2006-224M Settlement Lesnick 2006 $198 → $175
WEST 2016-0722 Dismissal Miller 2017 $114 → $114
Source: FMSHRC civil penalty dockets and decisions (public record), updated weekly.
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: 2024-06-25
10%
of limit-tested samples over the exposure limit
14
samples
10
limit-tested
Most sampled contaminants
  • Quartz, respirable, >1% Qtz111 over
  • Respirable dust, <.1mg3
Show the individual readings (14)
Date Contaminant Concentration Limit Conc / limit Occupation
2005-03-09 Quartz, respirable, >1% Qtz 2 1.35 1.48 Laborer, Bullgang
2024-06-25 Respirable dust, <.1mg 0 Front-end Loader Operator
2022-09-22 Quartz, respirable, >1% Qtz 0.2 Laborer, Bullgang
2022-09-22 Quartz, respirable, >1% Qtz 1 1.15 0.87 Laborer, Bullgang
2018-06-12 Quartz, respirable, >1% Qtz 0.29 0.62 0.47 Laborer, Bullgang
2018-06-12 Respirable dust, <.1mg 0 Laborer, Bullgang
2013-11-05 Respirable dust, <.1mg 0 Laborer, Bullgang
2009-06-16 Quartz, respirable, >1% Qtz 0.14 0.56 0.25 Laborer, Bullgang
2009-06-16 Quartz, respirable, >1% Qtz 0.13 1.1 0.12 Laborer, Bullgang
2005-05-12 Quartz, respirable, >1% Qtz 0.82 1.95 0.42 Laborer, Bullgang
2005-03-09 Quartz, respirable, >1% Qtz 0.62 1.13 0.55 Laborer, Bullgang
2001-05-08 Quartz, respirable, >1% Qtz 0.35 0.6 0.58 Complete Load-Haul-Dump
2001-05-08 Quartz, respirable, >1% Qtz 0.26 0.52 0.50 Supervisor, Co. Official
2001-05-08 Quartz, respirable, >1% Qtz 0.69 0.76 0.91 Hand Loader
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.
Ownership history
  1. Mariposa Flagstone Company 1950 to 1996
  2. Mariposa Flagstone Company 1997 to 2012
  3. Mariposa Yosemite Slate Quarry 2012 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 1
2025 1
2024 1
2023 1
2022 4
2021 1
2020 1
2019 2
2018 3
2017 2
2016 3
2015 3
2014 3
2013 3
2012 3
2011 3
2010 3
2009 4
2008 5
2007 4
2006 4
2005 4
2004 4
2003 4
2002 5
2001 5
2000 9
Source: MSHA quarterly employment and production, updated weekly.

Yosemite Slate Quarry sits in Mariposa County, California, 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.
Mariposa County, California · Population 17,060
0.0%
Mining share of county employment
$65,378
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 16 0 0 0.0
2026 Q1 9 0 0 0.0
2025 Q4 4 0 0 0.0
2025 Q3 12 0 0 0.0
2025 Q2 16 0 0 0.0
2025 Q1 16 0 0 0.0
2024 Q4 11 0 0 0.0
2024 Q3 13 0 0 0.0
Show 93 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2024 Q2 26 4 0 153846.2
2024 Q1 0 0 0
2023 Q4 0 0 0
2023 Q3 43 0 0 0.0
2023 Q2 36 0 0 0.0
2023 Q1 27 0 0 0.0
2022 Q4 1,399 0 0 0.0
2022 Q3 1,648 0 0 0.0
2022 Q2 1,419 0 0 0.0
2022 Q1 977 0 0 0.0
2021 Q4 203 0 0 0.0
2021 Q3 280 0 0 0.0
2021 Q2 290 0 0 0.0
2021 Q1 142 0 0 0.0
2020 Q4 191 0 0 0.0
2020 Q3 238 0 0 0.0
2020 Q2 103 0 0 0.0
2020 Q1 622 0 0 0.0
2019 Q4 1,292 0 0 0.0
2019 Q3 1,780 0 0 0.0
2019 Q2 685 0 0 0.0
2019 Q1 327 0 0 0.0
2018 Q4 438 0 0 0.0
2018 Q3 972 0 0 0.0
2018 Q2 1,512 0 0 0.0
2018 Q1 891 0 0 0.0
2017 Q4 1,297 1 0 771.0
2017 Q3 1,465 0 0 0.0
2017 Q2 1,464 0 0 0.0
2017 Q1 0 0 0
2016 Q4 253 1 1 3952.6
2016 Q3 1,549 0 0 0.0
2016 Q2 1,551 1 0 644.7
2016 Q1 1,251 0 0 0.0
2015 Q4 1,161 1 0 861.3
2015 Q3 1,594 0 0 0.0
2015 Q2 1,530 0 0 0.0
2015 Q1 1,500 0 0 0.0
2014 Q4 1,380 0 0 0.0
2014 Q3 1,296 0 0 0.0
2014 Q2 1,390 1 1 719.4
2014 Q1 1,248 0 0 0.0
2013 Q4 1,152 0 0 0.0
2013 Q3 1,620 0 0 0.0
2013 Q2 1,785 0 0 0.0
2013 Q1 1,380 1 1 724.6
2012 Q4 984 0 0 0.0
2011 Q2 1,035 0 0 0.0
2011 Q1 288 0 0 0.0
2010 Q4 691 0 0 0.0
2010 Q3 1,095 0 0 0.0
2010 Q2 1,614 0 0 0.0
2010 Q1 732 0 0 0.0
2009 Q4 821 0 0 0.0
2009 Q3 1,139 0 0 0.0
2009 Q2 1,244 0 0 0.0
2009 Q1 664 1 0 1506.0
2008 Q4 1,171 0 0 0.0
2008 Q3 1,473 0 0 0.0
2008 Q2 2,020 0 0 0.0
2008 Q1 1,564 0 0 0.0
2007 Q4 1,390 0 0 0.0
2007 Q3 2,003 3 0 1497.8
2007 Q2 1,805 0 0 0.0
2007 Q1 1,353 1 0 739.1
2006 Q4 1,077 0 0 0.0
2006 Q3 1,512 0 0 0.0
2006 Q2 1,498 0 0 0.0
2006 Q1 1,134 0 0 0.0
2005 Q4 1,112 0 0 0.0
2005 Q3 1,300 0 0 0.0
2005 Q2 1,338 2 2 1494.8
2005 Q1 1,223 0 0 0.0
2004 Q4 1,123 0 0 0.0
2004 Q3 1,169 0 0 0.0
2004 Q2 1,940 0 0 0.0
2004 Q1 1,552 0 0 0.0
2003 Q4 1,425 0 0 0.0
2003 Q3 1,930 0 0 0.0
2003 Q2 1,383 0 0 0.0
2003 Q1 2,178 0 0 0.0
2002 Q4 1,613 0 0 0.0
2002 Q3 2,448 0 0 0.0
2002 Q2 2,479 0 0 0.0
2002 Q1 2,068 0 0 0.0
2001 Q4 2,016 0 0 0.0
2001 Q3 2,285 0 0 0.0
2001 Q2 2,271 0 0 0.0
2001 Q1 1,854 2 1 1078.7
2000 Q4 1,677 0 0 0.0
2000 Q3 2,150 0 0 0.0
2000 Q2 1,952 0 0 0.0
2000 Q1 1,675 0 0 0.0
No fatalities recorded at this mine.

Reportable incidents

1 on file

2006 · 1 incident

January 20, 2006 CA · Metal/Non-Metal laborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitman HANDLING OF MATERIALS
Mariposa Flagstone Company · Caught in, under or between (Not Elsewhere Classified)

At 11 am EE rolled a rock on his right finger rt smashed the tip. Did not lose nail went to dr. and put in finger split.