Mining Incidents

MASONVILLE QUARRY: 130 MSHA citations Metal/Non-Metal

Controlled by Glenn E Southwick
Masonville, Larimer County, CO  ·  Active
MSHA Mine ID: 0504013

MASONVILLE QUARRY has $58K in proposed MSHA penalties and $0 outstanding across 5 contested dockets, plus health sampling and the full incident record.

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Fatalities
0
Total incidents
1
Years on record
2007
Latest incident
Jul 2007
Compliance record
MSHA citations since 2001
130
citations
37
significant & substantial
$57,673
proposed penalties
$52,201
paid to date
91% of proposed penalties paid to date, a $5,472 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2001
61
inspections on record
700
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: 700 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Imminent-danger orders
A Section 107(a) order removes miners from an area when an inspector finds an imminent danger. Each order is lifted once the condition is corrected, so this counts orders issued, not orders now in effect.
1
Section 107(a) orders
Most recent order: 2026-05-07.
On record since 2026.
Source: MSHA imminent-danger order records, updated weekly.

MASONVILLE QUARRY has $58K in proposed MSHA penalties and $0 outstanding across 5 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.
$58K
proposed penalties
$52K
current assessed
$52K
paid to date
$0
outstanding
111 assessments are final orders; 5 contested dockets.
Of $24K in penalties contested before the Commission, $19K was upheld in final decisions.
As of the most recent assessment on 2026-05-07.
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.
33.3%
significant & substantial
27.9%
high negligence or reckless
33.3%
reasonably likely or greater
51.4%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 3.6% low, 68.5% moderate, 27.9% 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.
7 citations taken to the federal commission · 5% of citations on record
  • Settled 7 · 100%
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 4 decided S&S contests · industry: 79%
23%
Penalty reduction in decided contests
$24K proposed, $19K 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 2016-10-19.
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 2013-147M Settlement Miller 2013 $12K → $8K
WEST 2013-276M Settlement Lesnick 2013 $4K → $4K
WEST 2013-489M Settlement Lesnick 2013 $4K → $4K
WEST 2013-853M Settlement Manning 2013 $4K → $2K
WEST 2015-284M Settlement Manning 2017 $243 → $175
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: 2024-04-10
29%
of limit-tested samples over the exposure limit
18
samples
7
limit-tested
Most sampled contaminants
  • Quartz, respirable, >1% Qtz72 over
  • Respirable dust, <.1mg11
Show the individual readings (18)
Date Contaminant Concentration Limit Conc / limit Occupation
2007-10-04 Quartz, respirable, >1% Qtz 0.3 0.26 1.15 Laborer, Bullgang
2007-07-31 Quartz, respirable, >1% Qtz 0.26 0.18 1.44 Stone Polisher/Cutter
2024-04-10 Respirable dust, <.1mg 0 Laborer, Bullgang
2024-04-10 Respirable dust, <.1mg 0 Front-end Loader Operator
2019-06-05 Respirable dust, <.1mg 0 Laborer, Bullgang
2019-06-05 Respirable dust, <.1mg 0 Laborer, Bullgang
2017-12-13 Respirable dust, <.1mg 0 Stone Polisher/Cutter
2017-12-13 Respirable dust, <.1mg 0 Stone Polisher/Cutter
2010-11-16 Quartz, respirable, >1% Qtz 0.21 0.3 0.70 Stone Polisher/Cutter
2010-11-16 Respirable dust, <.1mg 0 Stone Polisher/Cutter
2007-10-04 Quartz, respirable, >1% Qtz 0.14 0.24 0.58 Laborer, Bullgang
2007-10-04 Quartz, respirable, >1% Qtz 0.13 0.33 0.39 Laborer, Bullgang
2007-07-31 Respirable dust, <.1mg 0 Stone Polisher/Cutter
2007-07-31 Quartz, respirable, >1% Qtz 0.16 0.28 0.57 Stone Polisher/Cutter
2004-08-04 Respirable dust, <.1mg 0 Stone Polisher/Cutter
2004-08-04 Quartz, respirable, >1% Qtz 0.15 0.2 0.75 Stone Polisher/Cutter
2004-08-04 Respirable dust, <.1mg 0 Stone Polisher/Cutter
2004-08-04 Respirable dust, <.1mg 0 Stone Polisher/Cutter
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. Masonville Stone Company 1985 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 3
2025 2
2024 2
2023 2
2022 2
2021 2
2020 3
2019 2
2018 2
2017 3
2016 4
2015 4
2014 3
2013 3
2012 3
2011 3
2010 3
2009 4
2008 4
2007 5
2006 5
2005 5
2004 4
2003 5
2002 6
2001 5
2000 4
Source: MSHA quarterly employment and production, updated weekly.

MASONVILLE QUARRY sits in Larimer County, Colorado, where the Census mining category is 0.6% 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.
Larimer County, Colorado · Population 363,561
0.6%
Mining share of county employment
$91,364
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 1,300 5 3 3846.2
2026 Q1 750 0 0 0.0
2025 Q4 750 0 0 0.0
2025 Q3 900 0 0 0.0
2025 Q2 850 1 0 1176.5
2025 Q1 500 0 0 0.0
2024 Q4 750 2 0 2666.7
2024 Q3 750 0 0 0.0
Show 98 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2024 Q2 900 2 0 2222.2
2024 Q1 700 0 0 0.0
2023 Q4 900 2 0 2222.2
2023 Q3 930 0 0 0.0
2023 Q2 930 0 0 0.0
2023 Q1 400 0 0 0.0
2022 Q4 760 0 0 0.0
2022 Q3 930 0 0 0.0
2022 Q2 940 2 0 2127.7
2022 Q1 930 2 0 2150.5
2021 Q4 875 0 0 0.0
2021 Q3 875 0 0 0.0
2021 Q2 915 3 0 3278.7
2021 Q1 810 2 1 2469.1
2020 Q4 1,115 0 0 0.0
2020 Q3 1,240 0 0 0.0
2020 Q2 1,115 1 0 896.9
2020 Q1 810 1 0 1234.6
2019 Q4 875 0 0 0.0
2019 Q3 1,050 0 0 0.0
2019 Q2 625 2 0 3200.0
2019 Q1 590 0 0 0.0
2018 Q4 875 0 0 0.0
2018 Q3 930 1 0 1075.3
2018 Q2 940 0 0 0.0
2018 Q1 750 0 0 0.0
2017 Q4 810 2 1 2469.1
2017 Q3 925 0 0 0.0
2017 Q2 950 0 0 0.0
2017 Q1 1,156 0 0 0.0
2016 Q4 1,520 0 0 0.0
2016 Q3 1,600 1 0 625.0
2016 Q2 1,500 0 0 0.0
2016 Q1 1,200 1 0 833.3
2015 Q4 1,050 0 0 0.0
2015 Q3 1,850 0 0 0.0
2015 Q2 1,800 0 0 0.0
2015 Q1 1,400 0 0 0.0
2014 Q4 1,100 0 0 0.0
2014 Q3 1,235 5 2 4048.6
2014 Q2 1,200 0 0 0.0
2014 Q1 700 1 0 1428.6
2013 Q4 845 0 0 0.0
2013 Q3 1,120 0 0 0.0
2013 Q2 1,300 0 0 0.0
2013 Q1 850 0 0 0.0
2012 Q4 650 2 0 3076.9
2012 Q3 1,700 9 4 5294.1
2012 Q2 1,400 0 0 0.0
2012 Q1 1,250 0 0 0.0
2011 Q4 900 0 0 0.0
2011 Q3 1,400 3 2 2142.9
2011 Q2 1,380 0 0 0.0
2011 Q1 1,420 0 0 0.0
2010 Q4 520 10 3 19230.8
2010 Q3 1,200 0 0 0.0
2010 Q2 1,200 0 0 0.0
2010 Q1 600 1 0 1666.7
2009 Q4 900 4 2 4444.4
2009 Q3 1,200 2 1 1666.7
2009 Q2 1,800 0 0 0.0
2009 Q1 1,550 0 0 0.0
2008 Q4 1,200 0 0 0.0
2008 Q3 2,150 0 0 0.0
2008 Q2 1,800 0 0 0.0
2008 Q1 1,190 0 0 0.0
2007 Q4 1,000 1 0 1000.0
2007 Q3 1,930 37 12 19171.0
2007 Q2 1,420 0 0 0.0
2007 Q1 2,040 0 0 0.0
2006 Q4 1,500 0 0 0.0
2006 Q3 1,800 0 0 0.0
2006 Q2 2,250 0 0 0.0
2006 Q1 1,500 0 0 0.0
2005 Q4 1,200 0 0 0.0
2005 Q3 2,250 0 0 0.0
2005 Q2 2,200 0 0 0.0
2005 Q1 1,750 0 0 0.0
2004 Q4 900 0 0 0.0
2004 Q3 1,900 0 0 0.0
2004 Q2 1,600 0 0 0.0
2004 Q1 2,200 3 0 1363.6
2003 Q4 1,340 7 2 5223.9
2003 Q3 2,700 3 0 1111.1
2003 Q2 2,500 0 0 0.0
2003 Q1 1,500 0 0 0.0
2002 Q4 1,080 0 0 0.0
2002 Q3 2,500 2 0 800.0
2002 Q2 2,800 0 0 0.0
2002 Q1 1,920 0 0 0.0
2001 Q4 1,600 0 0 0.0
2001 Q3 0 2 2
2001 Q2 2,880 0 0 0.0
2001 Q1 2,800 0 0 0.0
2000 Q4 1,000 0 0 0.0
2000 Q3 480 0 0 0.0
2000 Q2 360 0 0 0.0
2000 Q1 1,500 0 0 0.0
No fatalities recorded at this mine.

Reportable incidents

1 on file

2007 · 1 incident

July 12, 2007 CO · Metal/Non-Metal superintendent SLIP OR FALL OF PERSON
Masonville Stone Company · Fall from machine

When releasing pressure from radiator cap, antifreeze gushed out burning foot. Operator jumped from loader and cracked foot bone on landing.