Mining Incidents

Round Mountain Rock: 83 MSHA citations Metal/Non-Metal

Round Mountain Rock · Surface
Westwood, Lassen County, CA  ·  Intermittent
MSHA Mine ID: 0405571

Round Mountain Rock has $16K in proposed MSHA penalties and $0 outstanding across 0 contested dockets, plus health sampling and the full incident record.

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Fatalities
0
Total incidents
0
Years on record
Latest incident
Compliance record
MSHA citations since 2004
83
citations
16
significant & substantial
$16,009
proposed penalties
$16,009
paid to date
100% of proposed penalties paid to date, a $0 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2004
29
inspections on record
406
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: 406 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.

Round Mountain Rock has $16K in proposed MSHA penalties and $0 outstanding across 0 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.
$16K
proposed penalties
$16K
current assessed
$16K
paid to date
$0
outstanding
81 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2023-11-30.
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.
19.8%
significant & substantial
4.9%
high negligence or reckless
19.8%
reasonably likely or greater
63.0%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 7.4% low, 87.7% moderate, 4.9% high, 0.0% reckless.
Source: MSHA violations gravity and negligence coding, 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: 2023-11-30
33%
of limit-tested samples over the exposure limit
10
samples
6
limit-tested
Most sampled contaminants
  • Quartz, respirable, >1% Qtz72 over
  • Respirable dust, <.1mg3
Show the individual readings (10)
Date Contaminant Concentration Limit Conc / limit Occupation
2015-10-21 Quartz, respirable, >1% Qtz 0.61 0.61 1.00 Crusher Oper/Worker
2015-08-25 Quartz, respirable, >1% Qtz 1.71 0.56 3.05 Crusher Oper/Worker
2023-11-30 Respirable dust, <.1mg 0 Backhoe Operator
2023-08-09 Quartz, respirable, >1% Qtz 0.23 Front-end Loader Operator
2015-10-21 Quartz, respirable, >1% Qtz 0.16 0.85 0.19 Front-end Loader Operator
2005-07-20 Respirable dust, <.1mg 0 Scale Man
2005-07-20 Quartz, respirable, >1% Qtz 0.55 1.32 0.42 Crusher Oper/Worker
2005-07-20 Respirable dust, <.1mg 0 Front-end Loader Operator
2005-07-20 Quartz, respirable, >1% Qtz 0.7 1.02 0.69 Crusher Oper/Worker
2005-07-20 Quartz, respirable, >1% Qtz 0.46 1.37 0.34 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.
Ownership history
  1. RLG Round Mountain Rock 2003 to 2012
  2. Round Mountain Rock 2012 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 2
2025 2
2024 2
2023 2
2022 2
2021 2
2020 2
2019 2
2018 3
2017 2
2016 3
2015 2
2014 3
2013 2
2010 1
2009 1
2008 9
2007 11
2006 9
2005 9
2004 9
2003 6
Source: MSHA quarterly employment and production, updated weekly.

Round Mountain Rock sits in Lassen 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.
Lassen County, California · Population 31,177
0.0%
Mining share of county employment
$64,395
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 704 0 0 0.0
2026 Q1 0 0 0
2025 Q4 1,919 0 0 0.0
2025 Q3 1,238 0 0 0.0
2025 Q2 794 0 0 0.0
2025 Q1 0 0 0
2024 Q4 775 0 0 0.0
2024 Q3 1,234 0 0 0.0
Show 70 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2024 Q2 815 0 0 0.0
2024 Q1 0 0 0
2023 Q4 915 4 0 4371.6
2023 Q3 654 19 4 29052.0
2023 Q1 0 0 0
2022 Q4 389 0 0 0.0
2022 Q3 1,337 0 0 0.0
2022 Q2 800 0 0 0.0
2022 Q1 0 0 0
2021 Q4 1,424 0 0 0.0
2021 Q3 838 0 0 0.0
2021 Q2 296 0 0 0.0
2021 Q1 0 0 0
2020 Q4 1,093 0 0 0.0
2020 Q3 1,731 1 1 577.7
2020 Q2 100 0 0 0.0
2020 Q1 0 0 0
2019 Q4 406 0 0 0.0
2019 Q3 1,028 0 0 0.0
2019 Q2 735 0 0 0.0
2019 Q1 0 0 0
2018 Q4 1,290 1 0 775.2
2018 Q3 1,833 0 0 0.0
2018 Q2 1,092 0 0 0.0
2018 Q1 0 0 0
2017 Q4 930 4 0 4301.1
2017 Q3 2,037 0 0 0.0
2017 Q2 1,470 0 0 0.0
2017 Q1 0 0 0
2016 Q3 1,229 0 0 0.0
2016 Q2 892 0 0 0.0
2016 Q1 0 0 0
2015 Q4 735 1 0 1360.5
2015 Q3 967 5 1 5170.6
2015 Q2 156 0 0 0.0
2015 Q1 20 0 0 0.0
2014 Q4 422 0 0 0.0
2014 Q3 830 3 0 3614.5
2014 Q2 1,032 0 0 0.0
2014 Q1 39 0 0 0.0
2013 Q4 591 0 0 0.0
2013 Q3 1,182 0 0 0.0
2013 Q2 677 0 0 0.0
2010 Q3 911 0 0 0.0
2010 Q2 200 0 0 0.0
2010 Q1 0 0 0
2009 Q4 0 0 0
2009 Q3 0 0 0
2009 Q2 120 0 0 0.0
2009 Q1 480 0 0 0.0
2008 Q4 2,264 5 0 2208.5
2008 Q3 5,258 0 0 0.0
2008 Q2 4,445 0 0 0.0
2008 Q1 640 0 0 0.0
2007 Q4 5,988 4 1 668.0
2007 Q3 3,695 3 0 811.9
2007 Q2 5,990 0 0 0.0
2007 Q1 763 0 0 0.0
2006 Q4 2,951 0 0 0.0
2006 Q3 4,794 6 1 1251.6
2006 Q2 2,567 0 0 0.0
2006 Q1 610 0 0 0.0
2005 Q4 1,906 0 0 0.0
2005 Q3 5,247 11 3 2096.4
2005 Q2 2,377 0 0 0.0
2005 Q1 670 0 0 0.0
2004 Q4 2,114 0 0 0.0
2004 Q3 3,881 11 5 2834.3
2004 Q2 3,255 2 0 614.4
2003 Q4 2,435 0 0 0.0

No reportable incidents on file.

MSHA has no recorded reportable accidents for this mine in the current dataset. New reports appear here within a week of being filed.