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Portable #4: 3 MSHA citations Metal/Non-Metal

Controlled by Knife River Corporation
Billings, Yellowstone County, MT  ·  Temporarily Idled
MSHA Mine ID: 2402047

Portable #4 has $445 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
2020
Latest incident
Aug 2020
Compliance record
MSHA citations since 2024
3
citations
0
significant & substantial
$445
proposed penalties
$445
paid to date
100% of proposed penalties paid to date, a $0 gap.
Source: MSHA violations data, updated weekly.
See Knife River Billings's full MSHA compliance history →
Inspection activity
MSHA inspections since 2020
7
inspections on record
100
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: 100 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.

Portable #4 has $445 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.
$445
proposed penalties
$445
current assessed
$445
paid to date
$0
outstanding
3 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2025-06-09.
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
33.3%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 33.3% low, 66.7% moderate, 0.0% 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: 2025-06-10
4
samples
0
limit-tested
Most sampled contaminants
  • Respirable dust, <.1mg4
Show the individual readings (4)
Date Contaminant Concentration Limit Conc / limit Occupation
2025-06-10 Respirable dust, <.1mg 0 Crusher Oper/Worker
2025-06-10 Respirable dust, <.1mg 0 Front-end Loader Operator
2020-07-01 Respirable dust, <.1mg 0 Front-end Loader Operator
2020-07-01 Respirable dust, <.1mg 0 Crusher Oper/Worker
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. Empire Sand & Gravel Company Inc 1994 to 2000
  2. Knife River Billings 2000 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 1
2025 1
2024 2
2023 3
2022 3
2021 3
2020 1
2019 2
2018 0
2017 0
2016 3
2015 0
2014 1
2013 2
2012 4
2002 0
2001 1
2000 0
Source: MSHA quarterly employment and production, updated weekly.

Portable #4 sits in Yellowstone County, Montana, where the Census mining category is 1.4% 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.
Yellowstone County, Montana · Population 167,340
1.4%
Mining share of county employment
$74,400
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 660 0 0 0.0
2026 Q1 0 0 0
2025 Q4 0 0 0
2025 Q3 1,217 0 0 0.0
2025 Q2 947 1 0 1056.0
2025 Q1 0 0 0
2024 Q4 136 0 0 0.0
2024 Q3 1,127 0 0 0.0
Show 51 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2024 Q2 874 2 0 2288.3
2024 Q1 0 0 0
2023 Q4 702 0 0 0.0
2023 Q3 1,686 0 0 0.0
2023 Q2 861 0 0 0.0
2023 Q1 478 0 0 0.0
2022 Q4 1,283 0 0 0.0
2022 Q3 2,439 0 0 0.0
2022 Q2 1,643 0 0 0.0
2022 Q1 1,378 0 0 0.0
2021 Q4 1,364 0 0 0.0
2021 Q3 3,042 0 0 0.0
2021 Q2 2,663 0 0 0.0
2021 Q1 0 0 0
2020 Q4 0 0 0
2020 Q3 1,609 0 0 0.0
2020 Q2 1,465 0 0 0.0
2020 Q1 0 0 0
2019 Q4 1,521 0 0 0.0
2019 Q3 2,548 0 0 0.0
2019 Q2 754 0 0 0.0
2019 Q1 0 0 0
2018 Q4 0 0 0
2018 Q3 0 0 0
2018 Q2 0 0 0
2018 Q1 0 0 0
2017 Q4 0 0 0
2017 Q2 0 0 0
2017 Q1 0 0 0
2016 Q4 244 0 0 0.0
2015 Q3 0 0 0
2015 Q2 0 0 0
2015 Q1 0 0 0
2014 Q4 0 0 0
2014 Q3 550 0 0 0.0
2013 Q3 0 0 0
2013 Q2 3,493 0 0 0.0
2013 Q1 311 0 0 0.0
2012 Q4 1,031 0 0 0.0
2012 Q3 1,215 0 0 0.0
2002 Q3 0 0 0
2002 Q2 0 0 0
2002 Q1 0 0 0
2001 Q4 0 0 0
2001 Q3 0 0 0
2001 Q2 186 0 0 0.0
2001 Q1 0 0 0
2000 Q4 0 0 0
2000 Q3 0 0 0
2000 Q2 0 0 0
2000 Q1 0 0 0
No fatalities recorded at this mine.

Reportable incidents

1 on file

2020 · 1 incident

August 20, 2020 MT · Metal/Non-Metal crusher attendant/operator, pan feeder operator/worker HANDLING OF MATERIALS
Knife River Billings · Struck by falling object

Employee was repairing the decking on a drop deck trailer upon which a generator sits. To access the decking a small transformer needed to be removed. While attempting to remove the transformer it fell striking the employee's left pinky finger lacerating it. Gloves were being worn.