United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued April 17, 2023 Decided July 7, 2023

No. 22-1143

GMS MINE REPAIR,

PETITIONER

v.

FEDERAL MINE SAFETY AND HEALTH REVIEW COMMISSION 

AND SECRETARY OF LABOR, MINE SAFETY AND HEALTH 

ADMINISTRATION (MSHA),

RESPONDENTS

On Petition for Review of a Decision of the

Federal Mine Safety and Health Review Commission

James P. McHugh argued the cause for petitioner. With 

him on the briefs was Christopher D. Pence.

Robert S. Wilson, Attorney, U.S. Department of Labor, 

argued the cause for respondent Secretary of Labor. With him 

on the brief was Emily Toler Scott, Counsel for Appellate 

Litigation.

Before: HENDERSON, MILLETT and CHILDS, Circuit 

Judges.

Opinion for the Court filed by Circuit Judge CHILDS.
2

CHILDS, Circuit Judge: In this petition for review, a mine 

operator and the Secretary of Labor dispute the meaning of a 

regulation that governs which safety and health violations are 

counted as part of an operator’s history when that operator

violates federal standards and must be assessed penalties. We 

conclude that the regulation at issue is ambiguous, the 

Secretary’s interpretation is reasonable, and that interpretation 

is entitled to deference. Therefore, we deny this petition. 

I

A

The Federal Mine Safety and Health Act of 1977 (Mine 

Act or Act) charges the Secretary of Labor (Secretary) with 

establishing and enforcing safety and health standards for the 

operation of the nation’s mines. W. Oilfields Supply Co. v. 

Sec’y of Labor and Fed. Mine Safety & Health Rev. Comm’n, 

946 F.3d 584, 586 (D.C. Cir. 2020). The Mine Act intended to 

remedy the shortcomings of two prior laws, the Federal Metal 

and Non-Metallic Mine Safety Act of 1966 and the Federal 

Coal Mine Health and Safety Act of 1969. S. REP. NO. 95-181, 

at 6–9 (1977). As the Senate identified in 1977, these two laws 

failed to protect miners from hazards, slowed the federal 

response time to emerging dangers, provided for penalties that 

were “much too low, and paid much too long after the 

underlying violation,” and created sanctions that were 

“insufficient to deal with chronic violators.” Id. at 8. 

To address these deficiencies, the Mine Act required the 

Secretary, through the Department of Labor’s Mine Safety and 

Health Administration (MSHA), to investigate accidents and 

conduct frequent inspections at mines throughout the calendar 

year. 30 U.S.C. § 813; see also Donovan v. Dewey, 452 U.S. 

594, 596 (1981). The Act also authorized the Secretary to 
3

promulgate mandatory standards and issue citations to 

operators who violate these standards. 30 U.S.C. §§ 811(a), 

814(a)–(b) and (d). An independent commission, the Mine 

Safety and Health Review Commission (the Commission), 

then assigns an administrative law judge (ALJ) to review 

contested citations and, where appropriate, impose proposed 

penalties against operators.1 30 U.S.C. §§ 820(a)–(c), 

823(d)(1). A five-person board constituting the Commission 

may, in its discretion, review an ALJ’s determination; 

otherwise, the ALJ’s determination becomes the final decision 

of the Commission. 30 U.S.C. § 823(d)(1). 

Ultimately, the penalties assessed by the MSHA must 

account for, among other things, “the operator’s history of 

previous violations . . . .” 30 U.S.C. § 820(i). The MSHA sets 

forth how it accounts for this history in Section 100.3(c) of its 

regulations, which considers violations “in a preceding 15-

month period” that “have been paid or finally adjudicated, or 

have become final orders of the Commission . . . .” 30 C.F.R. 

§ 100.3(c); see also III MSHA, Program Policy Manual 97 

(June 2012). Since 1982, the practice has been to include the 

violation “in an operator’s history as of the date it becomes 

final.” Criteria and Procedures for Proposed Assessment of 

Civil Penalties, 72 Fed. Reg. 13,592, 13,604 (Mar. 22, 2007)

(Preamble).

B

GMS Mine Repair and Maintenance, Inc. (GMS) is a 

mining contractor that provides “specialized services” to mines 

1 An “operator” is “any owner, lessee, or other person who 

operates, controls, or supervises a coal or other mine or any 

independent contractor performing services or construction at 

such mine.” 30 U.S.C. § 802(d).
4

in North America. Petitioner’s Br. iii. GMS provided contract 

services at the Mountaineer II Mine in West Virginia on April 

20 and 27, 2021, during which time the MSHA issued several 

citations against it. Although GMS stipulated to the “findings 

of gravity and negligence,” it contested the $7,331 proposed 

penalty. J.A. 75–76. Thereafter, GMS went before an ALJ to 

dispute the MSHA’s method of calculating the penalty, 

because it disagreed with “what precisely gets counted as the 

operator’s violation history . . . .” J.A. 78. 

The Secretary, representing the MSHA, argued that all 

citations and orders that have become final during the 

15-month look-back period are counted toward an operator’s 

history of violations, “regardless of when [the citations or 

orders] were issued.” J.A. 78. In opposition to this view, GMS 

argued that only violations whose citations or orders were both 

issued during the look-back period and were finalized during 

that period could count toward an operator’s history of 

violations. The ALJ deferred to the Secretary’s reading, 

deeming the regulation ambiguous “[o]n its face.” J.A. 78. 

GMS petitioned the Commission to review the ALJ’s 

determination, and when the Commission did not act, the 

ALJ’s determination became the final decision. Had the 

Commission accepted GMS’s reading, the company’s 

penalties would have been $3,268—roughly half the amount 

assessed. GMS timely petitioned this Court for review.

II

A

GMS raises factual arguments that we quickly reject 

before considering the remainder of its petition. GMS argues 

that the ALJ “misinterpreted certain material facts” and made 
5

an inappropriate “policy pronouncement” in the underlying 

decision. Petitioner’s Br. 41, 44. These arguments are

meritless because the ALJ accurately summarized GMS’s

position on which violations may be counted in an operator’s

history of violations, and the ALJ could factor into the analysis

a sampling of cases provided by the Secretary that reflected

common timelines for resolving penalty contests. J.A. 78–79. 

B

The Secretary has consistently maintained that violations 

that become final within the 15-month look-back period are to 

be included in an operator’s history of violations, but GMS’s 

position has been far less stable.2 At times, GMS alternatively 

argues for the inclusion of only:

1. Violations that occurred during the preceding 

15-month period. See Petitioner’s Br. 21 (“The 

language is clear and only refers to violations in 

the preceding 15 months. There is no reference 

to violations before 15 months as the Secretary 

assert[s].”);

2. Citations that were issued and finalized during 

the preceding 15-month period. See

Petitioner’s Br. 21 (“Any citation issued more 

than 15 months prior to the citation in dispute 

will not count because . . . only the citations 

issued in the preceding 15 months are part of the 

2

“When calculating an operator’s violation history for 

purposes of proposing a penalty amount, the Secretary 

considers the 15-month period immediately preceding the issue 

date of the citation/order that is being assessed.” J.A. 30. 
6

universe of relevant citations in this first step of 

the process.”); see also J.A. 76, ¶ 22; or

3. Violations that occurred and whose citations 

were issued and finalized during the preceding 

15-month period. Oral Arg. Tr. 7:4–9 (agreeing 

that “violation and citation and finalization . . . 

[must happen] all within 15 months”). 

GMS’s shifting interpretations might arise from its error 

of conflating a violation with a citation. It declares, without 

support, that it is “obvious[] a violation does not become a 

‘violation’ for purposes of [Section 100.3(c)] until a citation is 

issued.” Petitioner’s Br. 23. But that is untrue. Violations are 

the unlawful acts of an operator, while citations are the 

sanctions that the Secretary imposes as a result of those 

unlawful acts. See 30 U.S.C. § 814(a). These two words 

describe distinct events that take place at different points in the 

enforcement process—violations occur before citations are 

issued.3 

Notwithstanding the shifting interpretations, we take it 

that GMS asks for us to adopt its second reading, which is for

an operator’s history to include only citations that were both 

3 At oral argument, GMS continued to misuse these terms, 

referring to violations as occurring and being issued. Compare 

Oral Arg. Tr. 4:15–18 (asserting that “violation . . . means an 

occurrence under Webster’s . . . .”) (emphasis added), with 

Oral Arg. Tr. at 22:14–16 (“Nowhere in the Secretary’s 

argument does the Secretary explain where in the regulation it 

says that you can include violations that were issued four 

years ago.”) (emphasis added); cf. Petitioner’s Br. 23 (referring 

to “‘violations’ issued”). 
7

issued and finalized during the preceding 15-month period. 

This reading reflects GMS’s most consistent position. Unlike 

the other interpretations, GMS made this argument before the 

ALJ as well as in its briefs in support of its petition. Moreover,

GMS equates a violation with a citation, which aligns with its 

second interpretation requiring that a citation be issued and 

finalized during the look-back period. 

 

III

Our analysis of Section 100.3(c) is guided by the Supreme 

Court’s opinion in Kisor v. Wilkie, 139 S. Ct. 2400, 2415 

(2019), which provided clear instructions about how courts are 

to evaluate agency interpretations of regulations. 

First, courts must determine whether the regulation is 

“genuinely ambiguous” by “exhaust[ing] all the ‘traditional 

tools’ of construction.” Kisor, 139 S. Ct. at 2415 (quoting 

Chevron U.S.A., Inc. v. Nat. Res. Def. Council, Inc., 467 U.S. 

837, 843, n.9 (1984)). These traditional tools include the “text, 

structure, history, and purpose of [the] regulation.” Id. 

Second, even if a regulation is genuinely ambiguous, “the 

agency’s reading must fall ‘within the bounds of reasonable 

interpretation.’” Id. at 2416 (quoting City of Arlington v. FCC, 

569 U.S. 290, 296 (2013)). To this end, the work that courts 

do reviewing the text, structure, history, and purpose form the 

“outer bounds” of what is reasonable. Id. Lastly, courts must 

take a third step and identify the existence of “important 

markers for . . . [when] deference is . . . appropriate.” Id. What 

should persuade a court is the “character and context” of the 

agency interpretation—namely, the authoritativeness of the 

position asserted, implication of the agency’s substantive 

expertise, and whether the interpretation reflects the agency’s 

“fair and considered judgment.” Id. at 2416–17 (quoting 
8

Christopher v. SmithKline Beecham Corp., 567 U.S. 142, 155 

(2012)). 

For the reasons below, we conclude that Section 100.3(c)

is genuinely ambiguous, and the Secretary offers a permissible 

reading that is also entitled to deference. 

A

1

Of the tools that we must employ, “[t]he most traditional 

tool, of course, is to read the text[.]” Engine Mfrs. Ass’n v. 

EPA, 88 F.3d 1075, 1088 (D.C. Cir. 1996). Section 100.3(c) 

states, in relevant part:

100.3(c) History of Previous Violations

An operator’s history of previous violations is 

based on both the total number of violations and 

the number of repeat violations of the same 

citable provision of a standard in a preceding 

15-month period. Only assessed violations that 

have been paid or finally adjudicated, or have 

become final orders of the Commission will be 

included in determining an operator’s history. 

An “assessed” violation is one for which the Secretary has 

formally determined a civil penalty amount. See 30 U.S.C. 

§ 820(a)(1).

GMS contends that Section 100.3(c) includes only 

citations that were both issued within the preceding 15-month 

period and became final during that period as well. In GMS’s 

view, the first sentence of Section 100.3(c) “clear[ly]” refers to 
9

only citations in the preceding 15 months, because it omits any 

discussion of citations that may have occurred before this 

period. Petitioner’s Br. 21. Even more, the only qualification 

appears in the second sentence and restricts the scope of 

citations to ones that have also been finalized during that 

period. 

Seeing it differently, the Secretary argues that Section 

100.3(c) is not as clear as GMS asserts. The Secretary 

interprets Section 100.3(c) to apply to any violation that 

becomes final within the relevant 15-month period, regardless 

of when the violation occurred or when its citation was issued. 

To the Secretary, the first sentence of Section 100.3(c) 

establishes the relevant look-back period (15 months), and the 

second sentence merely clarifies that the field of violations to 

be considered must have become final during these 15 months. 

Between the two, the Secretary has the better argument. 

Section 100.3(c) speaks of only a look-back period and that the 

violations to be considered must have become final during that 

time. The regulation does not spell out the sequencing needed 

to compute an operator’s history (i.e., violation, citation, 

assessment, final order) and when each thing must occur. This 

lack of detail makes the regulation susceptible to competing 

interpretations, as seen in this dispute, which is why, based on 

the text alone, no single correct reading of the regulation 

emerges. 

2

Congress built into the Act a deliberate process for 

assessing and adjudicating violations; this process takes time 

to complete. Among its many provisions, the Mine Act permits 

inspections and investigations, 30 U.S.C. § 813(a); issuance of 

citations and follow-up orders; see, e.g., id. § 814(a)–(b), (d); 
10

procedures for enforcing those citations and orders, see 

generally id. § 815; injunctions, id. §§ 818(a)(1)–(2); and 

judicial review, see generally id. § 816. Clearly Congress was 

aware that each of these steps could take time, which it 

provided for in various other provisions of the Act. See, e.g., 

30 U.S.C. §§ 815, 823.

Despite these provisions, the statutory deadlines contained 

within them still do not account for the normal hindrances and 

happenstance that often prolong adjudicatory proceedings. 

The procedural history of this petition provides a case in point. 

Roughly two weeks after receiving the briefing schedule from 

our Court, GMS filed an unopposed motion for an extension of 

time to file its opening brief. We granted that unopposed 

motion a few days later. Similarly, GMS requested to 

reschedule oral argument, and we likewise obliged. These 

types of scheduling changes are as common during 

administrative proceedings as they are in courts of law. One 

can expect that such run-of-the-mill realities might easily push 

a contest outside of the 15-month timeframe that GMS argues 

must include all aspects of the process owed before a penalty

is imposed.

4

4 Although we concluded that GMS asks this Court to adopt its 

second and most consistent reading of the regulation, we pause

to comment on GMS’s position at oral argument. There, GMS 

argued that a violation, citation, and final adjudication must all 

occur within 15 months. Oral Arg. Tr. 7:4–9. As the 

Commission highlighted, pre-citation investigations can take 

longer than 15 months to complete. The Upper Big Branch 

mining disaster on April 5, 2010, cost the lives of twenty-nine 

miners and remains one of the deadliest mining accidents in 

recent history. Press Release, U.S. Dep’t of Lab., Statement by 

Sec’y of Lab. Marty Walsh on the Anniversary of the Upper 

Big Branch Explosion (Apr. 5, 2021), available at 
11

Given the amount of process afforded by the Mine Act, it 

is difficult to conclude that the process must be completed 

within 15 months of a citation being issued, or else a prior 

violation cannot be considered as part of an operator’s history. 

As such, the structure of the Mine Act favors the Secretary’s 

reading, because the Secretary’s reading does not restrict the 

process afforded to a fairly short 15 months. 

3

The history of the regulation also favors the Secretary’s 

reading. The Preamble reveals that the MSHA “anticipate[d] 

[the] issue” the Secretary now raises as to GMS’s proposed 

reading: the reading would encourage contests and thwart the 

Secretary’s ability to include violations in an operator’s 

https://perma.cc/R92S-ZD7T (last visited June 26, 2023). The 

MSHA did not issue contributory citations for this disaster

until it released its findings from the extensive investigation on 

December 6, 2011—twenty months after the disaster occurred. 

U.S. Dep’t of Lab., Proposed Assessment and Statement of 

Account, 1–2, Att. Narrative Findings for a Special 

Assessment (Dec. 6, 2011), available at 

https://perma.cc/QEZ9-EPA4 (last visited June 26, 2023).

Under GMS’s reading, operators, such as those who committed 

the serious violations leading to the Upper Big Branch disaster,

would never have their violations counted towards their 

history, because the Secretary issued the citations after an 

investigation that required more than 15 months to complete. 

So, though it might go without saying, GMS’s proposed 

reading could let operators escape accountability for even the 

most egregious violations of federal mine safety and health 

standards. 
12

history. Kisor, 139 S. Ct. at 2412; see also Preamble, 72 Fed. 

Reg. at 13,604. In 2007, the MSHA explained its intention to 

continue a longstanding practice of “us[ing] only violations 

that have become final orders of the Commission” and to 

include those violations “in an operator’s history as of the date 

[they] become[] final.” Preamble, 72 Fed. Reg. at 13,604. 

While the 2007 regulation shortened the look-back period

from 24 to 15 months, the MSHA remained keen on 

“retain[ing] the final order language” and a decades-long 

practice of a violation becoming a part of an operator’s history 

on the date that it became final. Id. at 13,604. Understanding 

this desire, the Secretary’s reading of the regulation comports 

with the regulation’s history as it reinforces the importance of 

finality rather than the lesser concerns—in this instance—of 

when the violation occurred or when the citations were issued. 

4

Congress enacted coal mining legislation keeping in mind 

“its most precious resource—the miner.” 30 U.S.C. § 801(a). 

The 1977 amendments expressly declared that the law intended 

“to prevent recurring disasters in the mining industry.” Fed.

Mine Safety and Health Act of 1977, Pub. L. No. 95-164, 91 

Stat. 1290 (1977). And to this end, Congress placed the 

“primary responsibility” on mine operators to prevent unsafe 

conditions and practices. 30 U.S.C. § 801(e). 

GMS’s reading might capture some routine violations 

where the operator pays the proposed penalty, but not contested 

violations or violations requiring special assessments. J.A. 42–

43; see also Oral Arg. Tr. 14:23–15:8. These latter violations

require longer to finalize, and under GMS’s restrictive reading

operators could avoid future consequences by prolonging

penalty contests. An interpretation leading to this result would
13

be “insufficient to deal with chronic violators” and could

hardly protect miners in the way Congress intended. S. REP.

NO. 95-181, at 8. 

B

Having reviewed the text, structure, history, and purpose,

we can conclude that Section 100.3(c) is genuinely ambiguous. 

While the structure, history, and purpose favor the Secretary’s 

reading, the text lacks useful detail. Nevertheless, the 

Secretary’s proposed interpretation falls within the “zone of 

ambiguity” created by our analysis of the regulation. Kisor, 

139 S. Ct. at 2416. 

The Secretary’s interpretation cares only about when the 

violation becomes final, which comports with the text. This 

interpretation falls within the zone of ambiguity, under which 

the second sentence (that discussesfinality) merely clarifiesthe

first sentence (that establishes the look-back period). These 

two sentences say nothing further about when the underlying 

violation must have occurred or been cited. Notably, like the 

regulation, the Secretary’s interpretation does not consider 

when the violation occurred or was cited. GMS’s reading, by 

contrast, requires us to infer an intention for citations to have 

been issued during the look-back period in addition to those 

citations being finalized during that period. We are not 

required to accept GMS’s reading, nor should we be inclined 

to infer the presence of terms that fail to make an appearance 

in the regulation’s plain text (here, the “issuance” of a 

“citation”). See Newman v. FERC, 27 F.4th 690, 698–99 (D.C. 

Cir. 2022) (declining to accept an interpretation that required 

our Court to infer the word “directly” as part of a regulation’s 

intended meaning). 
14

Equally, the Secretary’s reading also comes within the 

zone of ambiguity considering the structure, history, and 

purpose. The Secretary’s interpretation allows for operators to 

receive full process before being forced to pay penalties. Yet, 

it fulfills the purpose of the Act and implementing regulation 

by holding operators accountable for health and safety failures 

when determining an operator’s history of violations. The 

Secretary’s interpretation is thus reasonable and within our

established bounds.

C

Finally, we decide whether the Secretary’s interpretation 

warrants deference. Kisor, 139 S. Ct. at 2414. In other words, 

we examine “whether the character and context of the agency 

interpretation entitles it to controlling weight.” Id. at 2416. To 

do so, the interpretation must be the agency’s “authoritative or 

official position;” “implicate its substantive expertise;” and 

“reflect [its] ‘fair and considered judgment’” rather than evince 

an afterthought or litigation position. Id. at 2416–17 (citation 

and internal quotation marks omitted). The Secretary’s 

interpretation satisfies these criteria.

First, as the Preamble outlines, the Secretary’s 

interpretation reflects its official and steadfast practice (circa 

1982) of including a violation in an operator’s history as of the 

date the violation becomes final. See Kisor, 139 S. Ct. at 2416 

(citation omitted); see also Preamble, 72 Fed. Reg. at 13,604. 

The Preamble states that the MSHA included the phrase “final 

orders of the Commission” to clarify its intended continuance 

of this longstanding practice. Preamble, 72 Fed. Reg. at 

13,604. In presenting us with a policy followed for over four 

decades, the Secretary certainly does not offer a post-hoc 

rationalization or “convenient litigating position.” Kisor, 139 

S. Ct. at 2417 (quoting Christopher, 567 U.S. at 155). GMS 
15

and other operators have been familiar with the Secretary’s 

practice for quite some time. 

Second, the subject matter of the regulation is within the 

Secretary’s wheelhouse and implicates the Secretary’s 

expertise. Congress tasked the Secretary with developing 

regulations for mine safety as well as the methods used to 

enforce those regulations. As such, imposing penalties for 

violations and ensuring compliance with federal mine health 

and safety standards is neither “distan[t] from the agency’s 

ordinary duties,” nor does it “fall within the scope of another 

agency’s authority.” Kisor, 139 S. Ct. at 2417 (first alteration 

in original, second alteration omitted) (quoting Arlington, 569 

U.S. at 309). GMS counters that imposing sanctions does not 

implicate technical expertise because it is a procedural matter, 

which “[c]ourts deal with . . . far more than executive 

agencies.” Petitioner’s Br. 17. But Congress did not give 

courts the authority to determine when and how to assess mine 

safety violations. It delegated that authority to the Secretary. 

See 30 U.S.C. § 801 et seq. Besides, this may be one instance 

in which even “more prosaic-seeming questions . . . [still] 

implicate policy expertise,” which lies with the agency. Kisor, 

139 S. Ct. at 2417.

IV

For the foregoing reasons, we deny this petition. 

So ordered.