Sierra Minerals, LLC · Struck by... (Not Elsewhere Classified)
Employee was trimming timber with an electric chainsaw. The chainsaw became bound up and kicked back. The employee was struck with the chain above left elbow.
Colombo Mine: 12 MSHA citations Metal/Non-Metal
Sierra Minerals, LLC
· Underground
Controlled by
Sierra Resources, LLC; Elli M Mills
MSHA Mine ID: 0405951
Colombo Mine has $2K 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
- 1
- Years on record
- 2021
- Latest incident
- Apr 2021
Compliance record
MSHA citations since 2021
12
citations
0
significant & substantial
$1,500
proposed penalties
$1,500
paid to date
100% of proposed penalties paid to date, a $0 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2021
14
inspections on record
215
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: 215 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Colombo Mine has $2K 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.$2K
proposed penalties
$2K
current assessed
$2K
paid to date
$0
outstanding
12 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2021-10-21.
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.0.0%
significant & substantial
0.0%
high negligence or reckless
0.0%
reasonably likely or greater
58.3%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 41.7% low, 58.3% moderate, 0.0% high, 0.0% reckless.
Source: MSHA violations gravity and negligence coding, updated weekly.
Ownership history
- Sierra Minerals, LLC 2021 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
| Year | Employees |
|---|---|
| 2022 | 7 |
| 2021 | 8 |
Source: MSHA quarterly employment and production, updated weekly.
Colombo Mine sits in Sierra 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.Sierra County, California · Population 2,731
0.0%
Mining share of county employment
$60,000
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 |
|---|---|---|---|---|
| 2022 Q4 | 1,950 | 0 | 0 | 0.0 |
| 2022 Q3 | 2,416 | 0 | 0 | 0.0 |
| 2022 Q2 | 2,676 | 0 | 0 | 0.0 |
| 2022 Q1 | 4,533 | 0 | 0 | 0.0 |
| 2021 Q4 | 4,223 | 12 | 0 | 2841.6 |
| 2021 Q3 | 4,808 | 0 | 0 | 0.0 |
| 2021 Q2 | 3,590 | 0 | 0 | 0.0 |
| 2021 Q1 | 1,972 | 0 | 0 | 0.0 |
No fatalities recorded at this mine.