Data / Mines / Dimension slate

Dimension slate mines in the US: 34 open mines

MSHA lists 34 open dimension slate mines in the US, run by 26 operators and employing 223 people. Since January 1, 2022 its inspectors issued 514 citations and orders there with $172,803 in proposed penalties, and operators reported 16 injury or illness cases. The operators with the most open mines are Greenstone Slate Company; Newmont Slate Company Inc; VT Unfading Green Slate Company Inc. Data from MSHA, November 6, 2026.

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Open mines

34

Operators

26

Employees

223

Intermittent

18

Active

14

Temporarily Idled

2

Mines run by individuals, counted and not listed

3

Citations and orders since January 1, 2022

514

Significant and substantial

114 (22.2%)

Closure orders

27

High negligence or reckless

44

Proposed penalties

$172,803

Amount paid so far

$142,365

Inspections

341

Inspector hours on site

2,503

Citations per inspection

1.51 (all mines 2.30)

Accident reports

17

Injury and illness cases

16

Fatalities

0

Latest MSHA record

October 5, 2026

Operators with the most open mines

Ranked by open mines, then by citations. Sole proprietors and individuals are not listed.

Operators with the most citations

Citations and orders issued since January 1, 2022 at their open mines here.

Mines with the most citations

Open mines, ranked by citations and orders since January 1, 2022.

States

Citations and injury cases by year

Calendar years since 2022; 2026 runs to the date of the MSHA files.

Standards cited most at dimension slate mines

Sections of Title 30 of the Code of Federal Regulations named on the citations, with the part each belongs to.

Injury and illness cases at dimension slate mines

Accident reports by degree of injury, as the operator reported them to MSHA.

What the accident reports at dimension slate mines describe

Accident classification, as MSHA codes the circumstances that contributed most directly.

Equipment named in accident reports at dimension slate mines

Updated November 6, 2026. Read from US Department of Labor, Mine Safety and Health Administration (MSHA), Open Government Data Sets. US government work, public domain. Counts come from the MSHA files published on November 6, 2026. An open mine is one MSHA lists as Active, Intermittent, New Mine, Temporarily Idled or NonProducing; 13,673 were open that day. Citations, penalties, inspections and accident reports run from January 1, 2022. A citation is an inspector's allegation and an operator can contest it; the penalty is the amount MSHA first proposed, before any contest or settlement. An operator is the legal entity MSHA assesses, and a parent company is its controller. Mines run by sole proprietors or by individuals are counted in every total and are not named. This page uses MSHA data and is not endorsed or certified by MSHA. Free to reuse with credit to SpecStream under CC BY 4.0. Spot a wrong value? Write to [email protected] with the link to this page.