United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued December 15, 2022 Decided August 1, 2023

No. 22-1071

SECRETARY OF LABOR, MINE SAFETY AND HEALTH 

ADMINISTRATION,

PETITIONER

v.

KC TRANSPORT, INC. AND FEDERAL MINE SAFETY AND 

HEALTH REVIEW COMMISSION,

RESPONDENTS

On Petition for Review of a Decision of the

Federal Mine Safety and Health Review Commission

Susannah M. Maltz, Attorney, U.S. Department of Labor, 

argued the cause for petitioner. With her on the briefs was 

Emily Toler Scott, Counsel for Appellate Litigation.

James P. McHugh argued the cause for respondent KC 

Transport, Inc. With him on the brief was Christopher D. 

Pence. Thaddeus Jason Riley entered an appearance.

Before: WILKINS, WALKER, and PAN, Circuit Judges.
2

Opinion for the Court filed by Circuit Judge WILKINS.

Dissenting opinion filed by Circuit Judge WALKER.

WILKINS, Circuit Judge: Congress affirmed the 

importance of regulating effective health and safety standards 

within the mining industry when it enacted the 1977 Federal 

Mine Safety and Health Amendments Act (“Mine Act”), Pub. 

L. No. 95-164, 91 Stat. 1290 (1977) (codified as amended at 30 

U.S.C. § 801 et seq.). This dispute does not concern the 

substance of the Mine Act’s safety standards, but rather the 

jurisdictional boundaries to which they apply. 

KC Transport is an independent trucking company that 

provides various hauling services. Some of its clients include 

mining companies, and KC Transport used a facility, located 

over one mile from one of its client’s mining extraction sites, 

as a maintenance area. A Mine Safety and Health 

Administration (“MSHA”) inspector visited this area, after 

having inspected the nearby mine, and observed two of KC 

Transport’s trucks undergoing maintenance. Both trucks were 

raised, unblocked from motion, and one truck had a person 

standing underneath it. Because the trucks’ conditions violated 

safety standard 30 C.F.R. § 77.404(c), the MSHA inspector 

issued KC Transport two citations. KC Transport contested 

MSHA’s jurisdiction to issue the citations, arguing that the 

Mine Act does not apply. If the Mine Act does apply, however, 

KC Transport concedes that its trucks violated safety standards 

and the citations are thus valid. 

The Mine Act governs the regulation of “coal or other 

mine[s,]” 30 U.S.C. § 802(h)(1), as well as the activities of 

those who “operate[], control[], or supervise[,]” or “perform[] 

services or construction at such mine[s],” called “operator[s,]” 

id. § 802(d). Its jurisdiction covers all “mines,” which are 
3

defined by statute as: (A) extraction sites; (B) the “private 

ways and roads appurtenant” thereto; and (C) a list of items

“used in, or to be used in, or resulting from,” mining-related 

activity. Id. § 802(h)(1). 

In the proceeding on review challenging MSHA’s 

jurisdiction, the Federal Mine Safety and Health Review 

Commission (“Commission”) held that for the list of items, in

§ 802(h)(1)(C), to be considered a “mine,” the items had to be 

located at an extraction site, id. § 802(h)(1)(A), or the roads 

appurtenant thereto, id. § 802(h)(1)(B). Because neither the 

trucks nor the facility, associated with the citations at issue, 

were located on land covered under subsections (A)–(B), the 

Commission found they failed to constitute a “mine” and 

vacated the citations. The Commission also found that, as an 

independent contractor not engaged in servicing a mine at the 

time of citation, KC Transport failed to qualify as an “operator” 

under § 802(d) of the Mine Act.

The Secretary of Labor (“the Secretary”), acting through 

MSHA, appeals the Commission’s decision and asks us to 

uphold the two citations as an appropriate exercise of the 

Secretary’s jurisdiction under the Mine Act. In the Secretary’s 

view, subsection (C) of the “mine” definition covers KC 

Transport’s facility and trucks because they were “used in” 

mining activity. See § 802(h)(1)(C). 

Given the Mine Act’s language, context, and our binding 

precedent, we find that the Commission erred in its 

interpretation of the “mine” and “operator” definitions. And 

we generally defer to the Secretary’s reasonable interpretation 

of an ambiguous statute—even when the Commission 

disagrees. See Martin v. Occupational Safety & Health Rev.

Comm’n, 499 U.S. 144, 158 (1991); Excel Mining, 334 F.3d at 

6. But here, the Secretary’s position treats subsection (C) as 
4

unambiguous and makes no meaningful effort to address the 

numerous practical concerns that would arise under such an 

interpretation. Therefore, and in conformity with our 

precedent, we vacate and remand the Commission’s decision, 

allowing the Secretary to interpret the statute’s ambiguous 

language. See Sec’y of Lab. v. Nat’l Cement Co. of Cal., Inc.

(“National Cement I”), 494 F.3d 1066, 1077 (D.C. Cir. 2007). 

I.

A.

Congress enacted the Federal Coal Mine Health and Safety 

Act (“Coal Act”) in 1969 with the purpose of “improv[ing] 

mandatory health or safety standards to protect the health and 

safety of the Nation’s coal miners[.]” Pub. L. No. 91-173, 

§ 2(g), 83 Stat. 742, 743 (1969). As our nation’s use of mines 

continued, so too did the occurrence of mining-related 

incidents. For example, 226 miners tragically died from 

unexpected mine explosions in West Virginia, Ohio, and 

Pennsylvania in 1940 alone. See J. Davitt McAteer, The 

Federal Mine Safety and Health Act of 1977: Preserving a Law 

that Works, 98 W. Va. L. Rev. 1105, 1113 (1996). Additional 

incidents also took the lives of 119 miners in Illinois in 1951; 

78 miners in West Virginia in 1968; 91 miners in Idaho in 

1972; and 26 miners in Kentucky in 1976. Id. 

Because several forms of mine-related property were not 

enumerated in the Coal Act’s mine definition, incidents like the 

collapse of a retention dam left confusion as to whether the 

Coal Act’s protections applied. This lack of clarity put the 

Act’s jurisdictional bounds in question, prompting 

congressional action. Indeed, upon enacting the more 

comprehensive 1977 Mine Act, Congress cited the 1972 

collapse of the West Virginia retention dam—“result[ing] in a 
5

large number of deaths, and untold hardship to downstream 

residents[]”—as a reason to amend the “mine” definition. 

S. REP. NO. 95–181, at 14 (1977) (explaining the need to clarify 

the “mine” definition as “the Committee [was] greatly 

concerned that at [the time of the 1972 dam incident], the scope 

of the authority of the Bureau of Mines to regulate such 

structures . . . was questioned [under the Coal Act]”). 

The Mine Act established one regulatory scheme, covering 

the mining of coal, metals, and non-metals. See Sec’y of Lab.

v. Excel Mining, LLC, 334 F.3d 1, 3 (D.C. Cir. 2003) (citing 30 

U.S.C. § 961(a)). In doing so, Congress affirmed that “the first 

priority and concern of all in the coal or other mining industry 

must be the health and safety of its most precious resource—

the miner[.]” 30 U.S.C. § 801(a). It also aimed “to provide 

more effective means and measures for improving the working 

conditions” in American mines and “to prevent death[,] serious 

physical harm, and . . . occupational diseases[.]” Id. § 801(c). 

The Secretary is authorized to enforce this goal, and the Mine 

Act “created within the Department of Labor a new agency, 

[MSHA], to administer its provisions.” Am. Coal Co. v. 

FMSHRC, 796 F.3d 18, 21 (D.C. Cir. 2015). Under this 

structure, the Secretary “develop[s] and “promulgate[s]” 

“improved mandatory health or safety standards for the 

protection of life” in mines. 30 U.S.C. § 811(a). MSHA 

enforces these standards by conducting regular inspections, see

§ 813(a); issuing safety orders, see § 813(k); and issuing

citations for violations, see §§ 813(a), 815(a); for the Secretary 

to then assess and assign a corresponding penalty, see § 820(a). 

Any resulting citations, orders, or penalties may be reviewed 

by the Commission. In practice, mine operators may contest 

citations before an administrative law judge (“ALJ”), and 

either party may subsequently appeal the ALJ’s decision to the 

Commission. Am. Coal Co., 796 F.3d at 21.
6 

Given the nature of this case, it is important to emphasize 

that no part of this miner-safety-centered process applies absent 

jurisdiction. Whether property is subject to the Mine Act’s 

frequent inspections and other procedures is thus contingent 

upon whether the property constitutes a “mine.” A “coal or 

other mine” is defined under 30 U.S.C. § 802(h)(1) as:

(A) an area of land from which minerals are

extracted in nonliquid form or, if in liquid form,

are extracted with workers underground, (B)

private ways and roads appurtenant to such area,

and (C) lands, excavations, underground 

passageways, shafts, slopes, tunnels and

workings, structures, facilities, equipment, 

machines, tools, or other property including 

impoundments, retention dams, and tailings

ponds, on the surface or underground, used in, 

or to be used in, or resulting from, the work of 

extracting such minerals from their natural

deposits in nonliquid form, or if in liquid form,

with workers underground, or used in, or to be 

used in, the milling of such minerals, or the 

work of preparing coal or other minerals, and

includes custom coal preparation facilities. 

30 U.S.C. § 802(h) (emphases added). In sum, the statute’s 

jurisdiction over “mines” covers: (1) extraction sites; (2) the 

“private ways and roads appurtenant” thereto; and (3) a list of 

items “used in, or to be used in,” mining-related activity. Id. 

B.

The material facts are undisputed. See J.A. 4–13 (Joint 

Stipulations). KC Transport is an independent trucking 

company that operates truck maintenance and storage, and also 
7

provides hauling services to various businesses for different 

materials (e.g., coal, earth, and gravel). The following events 

took place at one of KC Transport’s locations—the Emmett 

facility located in Emmett, West Virginia. 

One of KC Transport’s clients is a coal mine operator 

named Ramaco Resources (“Ramaco”) that maintains five 

mines near the Emmett facility (“facility”). Ramaco’s 

representatives informed KC Transport that it could use the 

facility for maintenance, as Ramaco had no plans to operate a 

coal mine there. KC Transport accepted and began using the 

facility as its “maintenance area/shop.” J.A. 7. KC Transport 

also obtained commercial insurance covering the facility. 

At the time in question, the facility included only a parking 

area and two maintenance shipping containers. The facility 

was described as a “convenient centralized maintenance 

facility . . . for KC Transport,” J.A. 7, and KC Transport used 

it to operate about 35 trucks. Ramaco’s deep mines are about 

four to five miles away, and its strip mines are about six miles 

away. An estimated “60% of the [facility’s] services” 

supported Ramaco’s five nearby mines, and the remaining 40% 

of services aided other companies like “American Electric 

Power [] and other coal operators.” J.A. 7. The types of trucks 

at the facility are a mix of (1) off-road trucks, providing 

haulage for Ramaco’s five nearby mines; and (2) on-road 

trucks used in earth and gravel haulage for other customers, as 

well as coal haulage services for non-Ramaco customers. 

The facility is on Right Hand Fork Road located over one 

mile from one of Ramaco’s coal plants, the Elk Creek 

Preparation Plant. Right Hand Fork Road is a road off of the 

haulage road that runs past Elk Creek Plant and dead ends on 

the other side of the facility. The facility is about 1000 feet 

from the haulage road, and while the road leading “into the KC 
8

Transport facility is not a coal haulage road[,] [it] does branch 

off from a haulage road.” J.A. 6. The only way to access the 

facility is by advancing through a gate entrance on Right Hand

Fork Road, and while part of the haul-road is public, everything 

past the gate is reserved for authorized persons. During this 

time, however, the gate was not operational.

On March 11, 2019, an MSHA coal mine inspector visited 

Ramaco’s nearby Elk Creek Prep Plant. Although MSHA had 

never inspected, or even attempted to inspect, KC Transport’s 

trucks at the facility, MSHA regularly inspected KC 

Transport’s trucks along the haulage road, as well as at the Elk 

Creek Plant. Upon completing the Elk Creek Plant inspection, 

the inspector went “looking for trucks” that MSHA had 

previously cited and intended to terminate those citations. J.A. 

5; see 30 U.S.C. § 814(e)(3). The inspector traveled over a mile 

along the haulage road, turned off this road onto Right Hand 

Fork Road, continued along this road for about 1000 feet, and 

ultimately reached the facility. 

Upon arriving at the facility, the inspector observed KC 

Transport’s trucks undergoing maintenance. According to 

MSHA safety regulations, “[r]epairs or maintenance shall not 

be performed on machinery until the power is off and the 

machinery is blocked against motion, except where machinery 

motion is necessary to make adjustments.” 30 C.F.R. 

§ 77.404(c). Two of KC Transport’s trucks, however, were 

unblocked. Notably, because these particular trucks “were not 

licensed to haul products over public roads[,]” they were “only 

being operated on private land,” J.A. 10, and “regularly used to 

haul coal from the five Ramaco mines to the Elk Creek prep 

plant[,]” J.A. 8. At the time of inspection, the first truck was 

“jacked up with the wheels and tires off both back axles[,]” and 

“[w]ork [was] being performed on the brakes located on the 

back axles of the truck.” J.A. 30–31. The second truck was 
9

raised and a miner was underneath it, “standing on the frame of 

the truck[.]” J.A. 31; see J.A. 58. Because neither of the two 

trucks were “blocked against motion,” the inspector found KC 

Transport in violation of 30 C.F.R. § 77.404(c), and issued 

Citations Nos. 9222038 and 9222040.

C.

The primary issues in this litigation concern jurisdiction: 

(1) whether the facility or the two trucks constituted a “mine” 

under 30 U.S.C. § 802(h)(1)(C) of the Mine Act, such that 

MSHA had the authority to cite KC Transport for violating 

safety regulation 30 C.F.R. § 77.404(c); and (2) whether an 

independent contractor like KC Transport only qualifies as an 

“operator” under 30 U.S.C. § 802(d) when actively working at 

a mine site. If the Mine Act does apply, the parties agree both 

citations should be upheld and KC Transport owes a penalty 

fee of $3,908 regarding citation No. 9222038, and $4,343 

regarding citation No. 9222040. See J.A. 12–13. 

Once KC Transport contested the two citations, both the 

Secretary and KC Transport filed cross-motions, requesting 

summary decision of the jurisdictional issue. The ALJ rejected 

the parties’ interpretations of subsection (C), but ultimately 

ruled in MSHA’s favor and upheld the two citations as a proper 

exercise of the Mine Act’s jurisdiction. In the ALJ’s view, the 

facility and the mining-related equipment located therein were

too connected to the mining process to be excluded from the 

Mine Act’s jurisdiction. Thus, the ALJ found the facility 

constituted a “mine” under the subsection (C)’s plain meaning, 

“and because the trucks were used in mining and parked at the 

facility,” they qualified as “equipment” under subsection (C). 

J.A. 84.
10 

On appeal, a divided Commission reversed the ALJ’s 

finding of jurisdiction and vacated the two contested citations. 

According to the majority, 30 U.S.C. § 802(h)(1) 

unambiguously limits the “mine” definition to extraction sites 

and lands appurtenant thereto. Thus, the Commission held 

“that an independent repair, maintenance, or parking facility 

not located on or appurtenant to a mine site and not engaged in 

any extraction, milling, preparation, or other activities within 

the scope of subsection 3(h)(1)(A) is not a mine within the 

meaning of section 3(h) of the Mine Act.” J.A. 168. In a 

secondary holding, the Commission also found that KC 

Transport did not qualify as an “operator” under the Mine Act, 

because “[a]s an independent contractor, KC Transport is an 

operator subject to MSHA jurisdiction [only] while performing 

work at a mine site.” J.A. 165. One commissioner dissented, 

taking an even broader view than the ALJ, and argued that 

regardless of the facility, trucks constitute mines as they were 

“used in” mining and are “integral” to that process. J.A. 176. 

The Secretary filed a petition for review of the Commission’s 

decision. 

II.

We review the Commission’s legal findings de novo. See

Am. Coal Co., 796 F.3d at 23. “Under the Mine Act, the 

Secretary’s interpretation of the law must ‘be given weight by 

both the Commission and the courts.’” Excel Mining, 334 F.3d 

at 5–6 (quoting Sec’y of Lab. v. Cannelton Indus., Inc., 867 

F.2d 1432, 1435 (D.C. Cir. 1989) (quoting S. REP. NO. 95–181, 

at 49)). Should the Secretary and the Commission advance 

differing interpretations, “it is . . . the Secretary rather than the 

Commission who is entitled to the deference described in 

Chevron U.S.A. Inc. v. Natural Resources Defense Council, 

Inc., 467 U.S. 837 (1984).” Excel Mining, 334 F.3d at 6 

(cleaned up); see also Am. Coal, 796 F.3d at 23–24. But if the 
11 

Secretary incorrectly treats the statute as unambiguous, such 

that deference is not appropriate, we have previously remanded 

the case to the Commission, instructing the Secretary to 

interpret the statute in recognition of its ambiguities. See Sec’y 

of Lab. v. Nat’l Cement Co. of Cal., Inc. (“National Cement 

II”), 573 F.3d 788, 791 (D.C. Cir. 2009). 

A. 

 “Under these circumstances, the Secretary’s litigating 

position before the Commission is as much an exercise of 

delegated lawmaking powers as is the Secretary’s 

promulgation of a workplace health and safety standard.” 

Martin, 499 U.S. at 157. Accordingly, we turn to the 

Secretary’s argument, maintaining that the trucks at issue fell 

under the Mine Act’s jurisdiction under a plain reading of 

subsection (C). The Secretary maintains this Court should 

uphold the contested citations because 30 U.S.C. 

§ 802(h)(1)(C) unambiguously grants MSHA jurisdiction over 

both the trucks and the maintenance facility. Under this 

interpretation, subsection (C) unambiguously extends the Mine 

Act’s jurisdiction to cover each of the enumerated types of 

items if “used in, or to be used in” mining. Because the trucks 

are “equipment,” and because both the trucks and the facility 

were “used in” mining activity, the Secretary argues they 

satisfy the “mine” definition. 

Although advancing an opposing interpretation, the 

Secretary, like KC Transport in defending the Commission’s 

decision, asserts that the Act’s “mine” definition is 

unambiguous. As such, the Secretary urges us to uphold the 

citations as a proper exercise of MSHA’s jurisdiction under a 

plain reading of the statute. 
12 

This was the case in National Cement I, 494 F.3d at 1066. 

The central issue there was whether “a road National Cement 

use[d] to access its cement processing plant [] pursuant to a 

nonexclusive right-of-way grant” constituted a “mine” under 

30 U.S.C. § 802(h)(1). Id. at 1068. The Secretary defended its 

jurisdiction over the private road, arguing that because the road 

led to a cement processing plant, it unambiguously constituted 

a “private way[] and road[] appurtenant to” an extraction area 

under a plain reading of subsection (B), 30 

U.S.C. § 802(h)(1)(B). Finding subsection (B) ambiguous, we 

declined to “accord the Secretary’s litigating position Chevron

deference because she incorrectly treated the statute as 

unambiguous and interpreted it accordingly.” Nat’l Cement I, 

494 F.3d at 1073 (citing Peter Pan Bus Lines, Inc. v. Fed. 

Motor Carrier Safety Admin., 471 F.3d 1350, 1354 (D.C. Cir. 

2006) (“[D]eference to an agency’s interpretation of a statute 

is not appropriate when the agency wrongly believes that 

interpretation is compelled by Congress.” (internal quotation 

marks omitted))). 

As we explained, the statute’s use of the term “private” 

could encompass either a “group or class of persons,” or “a 

particular person[,]”—and similarly, “appurtenant” could 

mean a road either “subject to a transferable right of way 

benefitting the mine lessee,” or “dedicated exclusively to the 

use of the mine.” Nat’l Cement I, 494 F.3d at 1074. Thus, we 

vacated and remanded the Commission’s decision for the 

Secretary to interpret the ambiguous provision. On remand, the 

Secretary relied on two subsections and argued that subsection 

(B) extended over the road itself, while subsection (C) covered 

the mine-related vehicles traveling on the road. See 573 F.3d 

at 794. Satisfied that this interpretation reasonably accounted 

for the statute’s ambiguities, the National Cement II Court 

found “the Secretary’s interpretation of subsection (B)” was 

“entitled” to deference. Id. at 793. 
13 

Such an approach was not unique to National Cement I, as 

we took a similar path in Akzo Nobel Salt, Inc. v. Federal Mine 

Safety and Health Review Commission, 212 F.3d 1301, 1304–

05 (D.C. Cir. 2000). There, the Secretary asserted that a 

regulation unambiguously applied to and covered the citation 

at issue. We disagreed and found the regulation’s language 

ambiguous. The Secretary, however, “never grappled with” 

the “regulation’s clear ambiguity[,]” and because the Secretary 

had taken inconsistent positions, we vacated and remanded the 

Commission’s decision. Id. at 1305 (instructing the 

Commission to secure the Secretary’s regulatory interpretation, 

“and to resolve the case applying standard deference principles 

to that interpretation”).

To be clear, it is the Secretary’s litigating position 

resulting from a citation—not the Commission’s position—

that is ordinarily owed deference. See Excel Mining, LLC, 334 

F.3d at 6 (citing Martin, 499 U.S. at 157). We cannot defer, 

however, when the Secretary’s position mistakenly advances 

an interpretation compelled by Congress when the statute is in 

fact ambiguous. And as our case law shows, we have 

previously addressed such a mistake by remanding the case for 

the Secretary to account for the identified ambiguity. 

As we discuss below, here again, we are faced with a 

situation where the Secretary incorrectly asserts that the 

relevant text—30 U.S.C. § 802(h)(1)(C)—is unambiguous. 

Thus, we remand the case, allowing the Secretary to address

§ 802(h)(1)(C)’s ambiguities. 

Beginning with the statutory text, recall that § 802(h)(1) 

defines a “mine” as: (1) the physical extraction site, under 

subsection (A); (2) any “private ways and roads appurtenant” 

to that extraction site, under subsection (B); and (3) the items
14 

“used in, or to be used in, or resulting from” mining activity, 

under subsection (C). Congress’s inclusion of subsection (C) 

clarifies that the Mine Act extends beyond the land and roads 

covered in subsections (A)–(B). The Secretary argues the 

“mine” definition must be read so broadly that it incorporates 

each of subsection (C)’s items as an individual “mine.” Put 

differently, the Secretary advances a view under which all 

“machines, tools,” and even singular pieces of “equipment,” 

could constitute a “mine”—no matter their location—so long 

as they either were, or will be, “used in” mining activity. But 

certain “equipment[]”—like a truck—is mobile, and without a 

clear locational limit, it is impossible to ensure MSHA could 

monitor the equipment’s location and complete the statutorily 

mandated inspection requirements.

As indicated by its context, structure, and Congress’s use 

of the phrase “coal or other mine” throughout Chapter 22 of 

Title 30—location is central to the Mine Act. Consider the 

process through which MSHA ensures compliance with the 

Mine Act’s safety regulations. To start, Congress instructs that

“[e]ach operator of a coal or other mine subject to this chapter 

shall file with the Secretary the name and address of such 

mine[.]” 30 U.S.C. § 819(d) (emphases added). In addition to 

recording the mine’s location, Congress also instructed that 

each “coal or other mine” “shall” be inspected yearly, four 

times a year for “each underground coal or other mine[,]” and 

twice a year for “each surface coal or other mine.” Id. § 813(a). 

The statute delineates the limited circumstances under 

which the Secretary “may give advance notice of 

inspections[,]” and provides that authorized representatives 

“shall have a right of entry to, upon, or through any coal or 

other mine.” Id. (emphasis added). No discretion is accorded 

once the inspection is underway, and the Mine Act requires

inspectors to issue a citation upon belief “that an operator of a 
15 

coal or other mine” violated “any mandatory health or safety 

standard, rule, order, regulation, or order[.]” Id. § 814(a)). 

In addition to requiring a physical address for inspection 

purposes, the Mine Act also mandates that each “coal or other 

mine” operator “designate a responsible official” “in charge of 

health and safety” for each identified mine. Id. § 819(d). The 

Mine Act even outlines certain design requirements for every

identified mine. “At each coal or other mine there shall be 

maintained an office with a conspicuous sign designating it as 

the office of such mine.” Id. § 819(a). This office must also 

include “a bulletin board” near the entrance such that “orders, 

citations, notices and decisions required by law or regulation . 

. . may be posted[.]” Id. It is, thus, clear that no operator could 

comply with these provisions without first identifying a 

physical address for each of its mines. 

The Commission’s interpretation fares no better than the 

Secretary’s, because treating subsection (C) as inherently 

connected to subsections (A)–(B) cannot be harmonized with 

the statutory structure under which there are three separate and 

independent subsections. See id. § 802(h)(1)(A)–(C). If a 

“mine” is so clearly defined under subsections (A)–(B), what 

then to make of subsection (C)? Because the Commission finds 

it “clear that neither the purpose nor the language of the Act 

indicate a further geographical extension of jurisdiction under 

subsection (C)[,]” it reasons that subsection (C) must be read 

as “catalog[ing] various mining-related places . . . and objects” 

that are used in mining activity at physical extraction sites 

described in subsection (A), or the roads appurtenant thereto, 

described in subsection (B). J.A. 163–64; see Maxxim Rebuild 

Co. v. FMSHRC, 848 F.3d 737, 740 (6th Cir. 2017) (explaining 

that subsection (C) reads as though “the author went to a mine 

and wrote down everything he saw in, around, under, above, 

and next to the mine” and limiting the definition “only to 
16 

everything that one would see in or around a working mine” 

itself). Not so. 

One need only look to Congress’s concerns—cited when 

explaining its decision to revise the Coal Act’s “mine” 

definition—to conclude that subsection (C) was incorporated 

to specify that non-extraction site property may also constitute 

a “mine” when it (1) is “used in,” (2) will “be used in,” or (3) 

“result[s] from” the work of extracting or preparing minerals. 

30 U.S.C. § 802(h)(1)(C). As briefly mentioned in relation to 

the deadly mining-related incidents, subsection (C) was 

necessary—at least in part—to ensure the Mine Act’s 

jurisdiction extended to physical manifestations like dams that 

may be distant from the actual extraction site. Limiting 

jurisdiction to the land in subsections (A)–(B) would 

effectively omit subsection (C) and could exclude the very 

property Congress intended to cover. 

The Commission’s decision cannot stand for another 

fundamental reason: such a narrow view of 30 U.S.C. 

§ 802(h)(1) conflicts with this Circuit’s precedent under which 

we have clarified that the Mine Act extends beyond structures 

on extraction sites. In Donovan v. Carolina Stalite Co., we 

explained that the Mine Act “does not require that those 

structures or facilities [listed in subsection (C)] . . . be located 

on property where such extraction occurs.” 734 F.2d 1547,

1548, 1552 (D.C. Cir. 1984) (finding that a “slate gravel 

processing facility” placed on “property immediately adjacent 

to a quarry” fell under the Mine Act’s jurisdiction). 

Importantly, we also endorsed the view that MSHA’s 

“jurisdictional bases were expanded accordingly [in the 1977 

Mine Act] to reach not only the ‘areas . . . from which minerals 

are extracted,’ but also the ‘structures . . . which are used or are 

to be used in . . . the preparation of the extracted minerals.’” 

Id. at 1554 (quoting S. REP. NO. 95–181). This conclusion 
17 

applies equally to all property listed in subsection (C) which, 

as relevant here, includes both “structures” and “equipment.” 

Although the Secretary nominally recognized that the 

statute could be ambiguous, and advanced an alternative 

argument seeking our deference, at no point during this 

litigation did the Secretary grapple with the conflicting, 

practical implications of the advanced interpretation. See

Sec’y Br. 38–42; Sec’y Reply Br. 5, 14–17; Sec’y Supp. Br. 

11–13. Nor did the Secretary acknowledge the statute’s 

ambiguity as demonstrated by its historical background. For 

instance, when passing the 1977 Mine Act, Congress explained 

it would “enlarge[] the definition of ‘mine’ in [30 

U.S.C. § 802(h)] to include those mines previously covered by 

the [1966] Federal Metal and Non-Metallic, Mine Safety Act 

[‘Metal Act’].” S. REP. NO. 95–181, at 59; see Pub. L. No. 89-

577, 80 Stat. 772 (1966) (repealed 1977). The Metal Act fell 

under the Department of Interior, and the Mining Enforcement 

and Safety Administration (“MESA”) exercised the agency

enforcement role like the one MSHA occupies today. When 

referring to the Metal Act’s jurisdiction, a 1974 MESA-OSHA 

Memorandum of Understanding (“MOU”) explained that a 

“mine,” under this predecessor to the Mine Act, included 

“mineral extraction (mining) operations” as well as “milling 

and preparation facilities and other surface facilities used in 

mining or milling.” 39 Fed. Reg. 27,382, 27,383 (July 26, 

1974) (summarizing 30 U.S.C. § 721(b)). From this, MESA 

“interpret[ed] its authority to include the prescription and 

enforcement of standards regarding” a variety of operations, 

locations, and “transportation.” Id. But nowhere in the later 

1979 MSHA-OSHA MOU, pertaining to the 1977 Mine Act, is 

there any mention of MSHA’s authority as covering 

transportation. 44 Fed. Reg. 22,827, 22,827 (Apr. 17, 1979). 

What this might, or might not, signify—in relation to 

subsection (C)’s scope today—remains a mystery as the 
18 

Secretary’s briefs failed to discuss it. This lack of analysis 

further indicates the need to remand for the Secretary to engage 

with subsection (C)’s ambiguity. 

In the Secretary’s view, however, any risk of incorrectly 

broadening subsection (C) is mitigated by a functional analysis 

that officials conduct in determining whether certain facilities 

or equipment constitute a “mine.” Framed as a limitation, the 

Secretary argues that whether facilities or equipment constitute 

a “mine” depends only on a fact-based inquiry under which one 

must evaluate how closely related the relevant facility or 

equipment was to mining activity. Location is but one factor 

that may be relevant to this “use-in-mining” analysis. Oral Arg. 

Tr. at 10:3; see id. at 9–17; Sec’y Supp. Br. 13, 21. But such a 

fact-based inquiry does nothing to explain how MSHA might 

locate mobile equipment, such as the trucks at issue here, and 

fulfill its mandatory obligations to “make frequent 

inspections.” 30 U.S.C. § 813(a). Indeed, without an 

identifiable address, how will inspectors know where to find all 

equipment that has, or will be, “used in” mining? And how 

long after equipment is “used in” mining does it still qualify as 

a “mine” if no longer located on mine-related property? The 

Secretary’s broad and categorical view, although temptingly 

clear in theory, ultimately creates many more questions in 

practice. These questions bespeak ambiguity, and the 

Secretary’s litigation position must explain how they were 

taken into account. 

We note that all but three of the items enumerated in 

subsection (C) constitute physical manifestations. The 

physical manifestations—including, for example, “tunnels and 

workings, structures, facilities, . . . [and] retention dams[]”—

are similar to the extraction sites and roads outlined in 

subsections (A)–(B) because they are stationary and, thus, 

associated with a particular location. 30 U.S.C. § 802(h)(1)(C). 
19 

The three movable items—“equipment, machines, [and] tools,” 

id.—stand alone as property subject to much broader, nonmining related definitions. And as “[a] canon related to 

noscitur a sociis, ejusdem generis, counsels: ‘Where general 

words follow specific words in a statutory enumeration, the 

general words are usually construed to embrace only objects 

similar in nature to those objects enumerated by the preceding 

specific words.’” Yates v. United States, 574 U.S. 528, 545 

(2015) (cleaned up). One way of interpreting subsection (C) is 

therefore to view the three movable items included in the 

middle of the list in relation, and as connected, to the preceding 

physical manifestations. 

As applied here, there is at least a question of whether 

“equipment, machines, [and] tools,” when read within the 

wider Chapter 22 context, constitute “coal or other mine[s]” 

only when there is an established connection to the fixed 

physical manifestations listed before and after them. 30 U.S.C. 

§ 802(h)(1)(C). It is unclear, however, whether such an 

established connection impacts the circumstances under which 

the three movable types of property remain “mines” when not 

physically connected to the manifestations listed in subsections 

(A)–(C). At a minimum, the statutory language, broader 

context, and numerous practical concerns render subsection 

(C)’s meaning ambiguous. 

Our dissenting colleague contends that “an item listed in 

subsection (C) must be located at an extraction site or a 

processing plant to count as a ‘mine’ under the Act.” 

Dissenting Op. 8. This restrictive construction of the statute 

countermands our observation in Donovan that the Act 

included a “sweeping definition of a mine[,]” 734 F.2d at 1554

(internal quotation marks omitted), as well as our ruling in 

National Cement II that the “broad statutory definition of 

‘mine[]’ . . . extends the protections of the Mine Act beyond 
20 

the actual site where mining takes place.” 573 F.3d at 795. The 

dissent’s interpretation also contradicts our recognition in 

National Cement I that, as a procedural matter, the Secretary 

should “confront” the breadth and ambiguity of the Act in the 

first instance. 494 F.3d at 430. In that case, we held that 

because the definitional terms of “mine” in subsection (B) of 

the Mine Act “are ambiguous and the Secretary instead 

interpreted them as having a plain, unambiguous meaning, we 

vacate the Commission’s decision and remand for it to obtain 

from the Secretary a Chevron step 2 interpretation[.]” Id.; see 

also Akzo Nobel Salt, Inc., 212 F.3d at 1304–05 (explaining 

that while the Secretary asserted that a Mine Act regulation 

unambiguously applied, we found the regulation’s language 

ambiguous and remanded for the Secretary to “grappl[e] with” 

the “regulation’s clear ambiguity”). We are of course bound 

by our precedent. LaShawn A. v. Barry, 87 F.3d 1389, 1393 

(D.C. Cir. 1996). The dissent’s oversimplification also elides 

the interpretive difficulty that arises when a truck is cited while 

located on an extraction or processing site, but MSHA later 

goes looking for the truck outside the extraction or processing 

area to determine whether the cited violations have been 

abated—which is exactly how the present dispute began. See 

supra at 8; J.A. 5. Does the statute unambiguously provide that 

MSHA loses jurisdiction over a truck once it leaves the 

extraction or processing area? Apparently so, under the 

dissent’s view. But that reading of the statute renders 

enforcement of the Mine Act unworkable, frustrating 

Congress’s intent. 

B. 

The Commission’s secondary ruling, concerning the Mine 

Act’s “operator” definition, faces a similar fate as its first. An 

“operator” is defined under § 802(d) as “any owner, lessee, or 

other person who operates, controls, or supervises a coal or 
21 

other mine or any independent contractor performing services

or construction at such mine[.]” 30 U.S.C. § 802(d) (emphasis 

added). To further confirm that the Secretary lacked 

jurisdiction to issue the citations, the Commission held that KC 

Transport failed to qualify as an “operator” under the Mine Act. 

It reasoned that “[a]s an independent contractor,” KC Transport 

only qualifies as “an operator subject to MSHA jurisdiction 

while performing work at a mine site[,]” and “[w]hen the 

citations were issued” here, “KC Transport was not performing 

services in a mine.” J.A. 165. Because the trucks were parked 

and off the mine site, “KC Transport was not performing 

services in a mine[]” when the two citations were issued and, 

therefore, was not an “operator.” Id. 

The Secretary asks us to vacate the ruling, not only 

because the Commission incorrectly narrowed the 

circumstances under which an independent contractor qualifies 

as an “operator” under the Mine Act, but also because it 

exceeded its jurisdiction by deciding an unraised issue in the 

first instance. We find it especially telling that KC Transport 

chooses not to defend the Commission’s “operator” ruling on 

the merits. Instead, KC Transport insists this is a non-issue, 

because rather than a secondary holding, the Commission 

merely quoted statutory language discussing “operators” to 

further support its “mine” definition ruling. This argument is 

clearly rebutted by the record, revealing the Commission found 

KC Transport “was not an operator under section 3(d)” because 

it “was not performing services in a mine[.]” J.A. 165. We 

therefore review the Commission’s secondary “operator” 

holding and find it lacked jurisdiction to make such a ruling. 

The Commission’s jurisdiction is limited to questions that 

were reviewed by the ALJ, and then included in the petition for 

discretionary relief on appeal. See 30 U.S.C. § 823(d)(2). 

However, the record shows that the ALJ never considered KC 
22 

Transport’s “operator” status. As the parties’ joint stipulations 

confirm, KC Transport conceded that its trucks’ conditions 

violated 30 C.F.R. § 77.404(c) “should the [ALJ] find that 

MSHA did have jurisdiction over the trucks[.]” J.A. 12

(emphasis added). KC Transport then repeated this concession 

in its briefs before the ALJ, and both parties advanced 

arguments that focused exclusively on the Mine Act’s 

jurisdiction concerning the trucks and, or, the facility. Neither 

party so much cited 30 U.S.C. § 802(d)’s “operator” definition, 

and there is no trace of such a discussion in the ALJ’s decision. 

See J.A. 75 (“The parties have stipulated that should this Court 

find that MSHA had jurisdiction over the trucks and location, 

the cited conditions would constitute violations of 30 C.F.R. 

§ 77.404(c)[.]”). And the parties maintained the same focus on 

30 U.S.C. § 802(h)(1)’s “mine” definition before the 

Commission. Thus, KC Transport’s “operator” status was not 

questioned until the Commission issued its majority decision. 

Because the Commission resolved this unraised issue on 

its own without the benefit of briefing—and in the first 

instance—it failed to abide by its jurisdictional boundaries 

under 30 U.S.C. § 823(d)(2). And although there is a process 

through which the Commission may exercise its discretion to 

reach additional issues, see id. § 823(d)(2)(B), nothing in the 

record shows it followed that procedure here. 

* * * 

To be sure, the Mine Act is intentionally broad, and this 

characteristic helps enable the government to protect and 

promote miner safety. Am. Coal Co., 796 F.3d at 25. We 

reiterate, however, that broad authority does not equate 

limitless jurisdiction. Nat’l Cement I, 494 F.3d at 1077. It is 

the courts’ role to ensure this broad authority is exercised 

within its jurisdictional bounds, and we use a variety of tools 
23 

to do so. Ensuring that the Secretary adopts a reasonable 

interpretation of its jurisdiction by grappling with the questions 

and challenges posed by an ambiguous statute is one of the 

devices in our toolkit. But without such an interpretation here,

there is nothing to which we may defer. Id. at 1075. Heeding 

the lessons of National Cement I & II, we vacate the 

Commission’s decision and remand for the Secretary to 

reconsider its position pursuant to a revised interpretation of 

subsection (C), after recognizing its ambiguity and addressing 

the questions outlined in this opinion. See id. at 1077. 

 So ordered.
WALKER, Circuit Judge, dissenting:

KC Transport is a small trucking company. It occasionally 

uses its trucks to haul coal for nearby mines. When those trucks 

break down, KC repairs them at its truck-repair shop — some

four miles away from the nearest mine. 

Because KC’s shop repairs mining trucks, the Secretary of 

Labor says the shop is a “mine.” In his view, any “facilit[y]” 

“used in . . . the work of extracting [coal]” is a “mine” under 

the Mine Act. 30 U.S.C. § 802(h)(1). And that puts KC’s 

truck-repair shop within the Mine Safety and Health Administration’s jurisdiction. 

I disagree. To count as a “mine,” a “facility” like KC’s 

shop must be located at an extraction site or a processing plant. 

KC’s shop is not. So the Administration lacks jurisdiction over 

it. 

I would thus deny the Secretary’s petition for review. 

I. Background

A. Mine Safety and Health Administration’s Jurisdiction

The Mine Act tasks the Secretary of Labor with setting 

health-and-safety standards for mines. 30 U.S.C. § 811. To 

enforce those standards, the Mine Safety and Health Administration must “make frequent inspections and investigations” 

of “mines.” Id. § 813(a); see 29 U.S.C. § 557a. If a mine operator fails to meet the agency’s safety standards, it may issue

a citation. 30 U.S.C. §§ 813, 802(d) (a mine “operator” “operates, controls, or supervises a . . . mine”). 

Because the Administration may inspect and cite only 

“mines,” its jurisdiction depends on the Mine Act’s definition 

of “coal and other mines”: 
2

(A) an area of land from which minerals are extracted in nonliquid form or, if in liquid form, 

are extracted with workers underground,

(B) private ways and roads appurtenant to such area, 

and

(C) lands, excavations, underground passageways, 

shafts, slopes, tunnels and workings, structures, 

facilities, equipment, machines, tools, or other 

property including impoundments, retention 

dams, and tailings ponds, on the surface or underground, used in, or to be used in, or resulting from, the work of extracting such minerals 

from their natural deposits in nonliquid form, 

or if in liquid form, with workers underground, or used in, or to be used in, the milling

of such minerals, or the work of preparing

coal or other minerals, and includes custom 

coal preparation facilities.

Id. § 802(h)(1) (emphases added). 

Here, we must decide if a truck-repair shop that occasionally fixes mining trucks is a “mine” within the Administration’s 

jurisdiction. 

B. KC Transport’s Citations

KC Transport has a contract to haul coal at Ramaco Resources’ mines near Emmett, West Virginia. To help KC with 

the job, Ramaco lets KC use a patch of land off a private road 

near the mines to maintain its trucks. KC built a parking lot on 

the land and installed two shipping containers to use as a 

maintenance shop. 
3

KC’s shop is about a mile away from Ramaco’s coal-processing plant and more than four miles away from Ramaco’s 

nearest extraction site. In addition to its arrangement with Ramaco, KC uses trucks from the shop to serve customers that 

don’t mine coal (or anything else). For instance, it has a “large 

earth moving project” for a different company. JA 7. 

In 2019, a mine-safety inspector visited KC’s repair shop. 

He noticed that KC was servicing two dump trucks, but had not

taken sufficient precautions to prevent the truck beds from 

moving during maintenance. That, the inspector decided, was

a violation of the Administration’s regulations. 30 C.F.R. 

§ 77.404(c). So he issued KC two citations, one for each truck. 

Rather than pay the citations, KC challenged them before 

the Mine Safety Commission. It argued that the Administration 

lacked jurisdiction to issue the citations. The agency may issue 

citations only to “an operator of a coal or other mine,” and, KC 

pointed out, its repair shop is not a “mine.” 30 U.S.C. § 814(a).

An administrative law judge rejected KC’s challenge, 

holding that its shop is a “mine” under the Act. Because repairing mining trucks is “essential to the coal hauling and preparation process,” JA 91, the ALJ reasoned that the shop is a 

“facilit[y]” that is “used in . . . the work of extracting . . . minerals.” 30 U.S.C. § 802(h)(1)). 

On appeal, the Commission reversed. It held that the 

ALJ’s reading of the statute divorced select words in the definition of “mine” from their context. The full definition — quoted above — is filled with geographic language 

suggesting that a facility must be close to an extraction site to 

count as a mine. Id.§ 802(h)(1). Because KC’s shop is “distant 

from a mine site, owned by an independent company, and used 
4

for parking and repairing its vehicles,” it did not count as a 

“mine.” JA 164. So the agency lacked jurisdiction over it. 

Unhappy with the Commission’s decision, the Secretary 

petitioned this court for review, challenging the Commission’s 

interpretation of the Mine Act. I would deny the Secretary’s 

petition.1

II. KC’s Shop Is Not A “Mine”

KC’s truck-repair shop is not a “mine” under the Mine Act

because it is not located at an extraction site or at a processing 

plant (where minerals like coal are milled or prepared, turning 

them from ore into usable products). 

A. The Act’s Definition of “Mine” Has Geographic Limits

Though the Mine Act’s definition of “mine” has no express geographic limit, the statute’s “carefully calibrated 

scheme” confirms that there is one. Turkiye Halk Bankasi A.S. 

v. United States, 143 S. Ct. 940, 947 (2023) (looking to the 

statutory scheme to cabin the reach of a seemingly broad statutory provision); Antonin Scalia, A Matter of Interpretation 24 

(1997) (“the good textualist is not a literalist”).

1 “[A] constitutional quandary [is] raised by a federal court resolving 

a lawsuit,” like this one, “between two Executive Branch agencies.” 

United States Postal Service v. Postal Regulatory Commission, 963 

F.3d 137, 143 (D.C. Cir. 2020) (Rao, J, concurring). “[S]uch disputes do not appear to constitute a case or controversy for purposes 

of Article III,” because “agencies involved in intra-Executive Branch 

disputes are not adverse to one another (rather, they are both subordinate parts of a single organization headed by one CEO).” SEC v. 

FLRA, 568 F.3d 990, 997 (D.C. Cir. 2009) (Kavanaugh, J., concurring). Our precedents, however, allow such suits to proceed. 
5

Recall that the Act defines “mine” in three subsections. 30 

U.S.C. § 802(h)(1). To count as a mine, a facility must meet 

the criteria in one of those subsections. Secretary of Labor v. 

National Cement Co. of California, Inc., 573 F.3d 788, 795

(D.C. Cir. 2009) (each subsection independently defines 

“mine”).

Two subsections have express geographic limits: Subsection (A) extends only to excavation sites, covering “area[s] of 

land from which minerals are extracted,” and subsection (B) 

includes “roads appurtenant to such area[s].” 30 U.S.C. 

§ 802(h)(1).

That leaves us with subsection (C). It’s a catch-all list of 

additional things that may count as mines if they are “used in” 

“extracting,” “preparing,” or “milling.” Id. § 802(h)(1)(C). 

That list breaks down into three categories:

• Structures found at excavation sites: “excavations, underground passageways, shafts, slopes, tunnels and 

workings.” 

• Generic items: “lands, . . . structures, facilities, equipment, machines, tools.” 

• Structures found at preparation plants: “impoundments, retention dams, and tailings ponds.”2

2 “Tailings” are a waste product generated by coal processing. They 

are a “residue separated in the preparation of various products (such 

as grain or ores).” Tailing (def. 1), Merriam-Webster (2023). 

“[I]mpoundments, retention dams, and tailings ponds” are all structures used to store tailings. 30 U.S.C. § 802(h). An “impoundment” 

is a generic term for a structure used to “retain tailings.” Technical 

Report: Design and Evaluation of Tailings Dams, EPA, at 5 (Aug. 

1994), https://perma.cc/68LA-UJRF. A “retention dam” is a method 

of storing tailings in which the “dam[] [is] constructed at full height 
6

Because words “are known by their companions,” it makes 

sense to read the generic items in light of the two other categories in the list. Gutierrez v. Ada, 528 U.S. 250, 255 (2000). 

Doing so suggests that lands, structures, facilities, and equipment must either be at an excavation site or at a processing 

plant to count as “mines” under the Act. Cf. Donovan v. Carolina Stalite Co., 734 F.2d 1547, 1548, 1552 (D.C. Cir. 1984)

(subsection (C) “does not require” that processing facilities “be 

located on property where . . . extraction occurs,” so a processing facility “immediately adjacent to a quarry” was a 

“mine”).

Reading the Act that way reveals a geographic limit that 

neatly mirrors the Act’s express functional limit. Under the 

Act’s functional limit, no item on the list in subsection (C) 

counts as a “mine” unless it is “used in, or to be used in, or 

resulting from, the work of extracting . . . minerals . . . or . . .

the milling of such minerals, or . . . preparing coal or other minerals.” 30 U.S.C. § 802(h)(1)(C).3

 Because milling is a type

of coal preparation, the Act’s functional test boils down to asking whether an item on the list is used in extracting or 

at the beginning of the disposal” (in other retention designs the height 

of the embankment is increased as tailings are added). Id. at 6. And 

a tailings “pond” is a body of wastewater held in by a dam or impoundment. See id. at 30.

3 Milling involves grinding coal into smaller chunks so that it is commercially usable. See Peter T. Luckie & Leonard G. Austin, Coal 

Grinding Technology, Dept. Energy (1980), https://perma.cc/EW37-

MDVA (describing how several types of coal mills operate). Coal

preparation involves extracting coal from the raw material extracted 

at a mine site. See 30 U.S.C. § 802(i) (defining the “work of preparing the coal” as covering the gamut of coal processing: “breaking, 

crushing, sizing, cleaning, washing, drying, mixing, storing, and 

loading”). 
7

processing coal. Similarly, the Act’s geographic limit asks 

whether an item is at an extraction site or a processing plant. 

Now consider the Secretary’s literal reading of the statute. 

The Secretary contends that the Administration’s jurisdiction 

depends only on function, not location. Pet. Br. 16. In the Secretary’s view, any “piece of equipment” or “facility” can be a 

mine, no matter where it is located. Id.

The rest of the statute shows why that reading doesn’t 

work. Many of the Act’s provisions assume that a “mine” has 

a readily identifiable location. Thus, mine “operator[s]” must 

“file with the Secretary” their mine’s “name and address.” 30 

U.S.C. § 819(d). And at “each . . . mine” there must be “an 

office with a conspicuous sign designating it as the office of 

such mine.” Id. § 819(a). Similarly, the Mine Safety and 

Health Administration must annually inspect each “coal or 

other mine.” Id. § 813(a). 

Those requirements would make no sense if a mine’s location was unfixed. 

Take an example. An independent contractor uses his 

truck for a mining job each Wednesday. The rest of the week 

he drives his truck 200 miles away for use on a construction 

site. Even when it’s 200 miles away, that truck is a “mine” on 

a literal reading of the statute: It is a “machine[]” that is “used 

in, or to be used in, . . . the work of extracting . . . minerals.”

Id. § 802(h)(1). Yet that result clashes with the Act’s commands to install “an office with a conspicuous sign” and to file 

a mine’s “name and address.” Id. § 819(a), (d); see also 

Maxxim Rebuild Co., LLC v. Federal Mine Safety & Health 

Review Commission, 848 F.3d 737, 742 (6th Cir. 2017) (noting 

that “other definitions in the Mine Act portray a mine as a 

place”). 
8

The literal reading’s problems only deepen from there. 

The Act covers “independent contractor[s]” when they are 

“performing services or construction at [a] mine.” 30 U.S.C.

§ 802(d). But if the Act has no geographic limit, the agency 

could inspect contractors anywhere they go — including at

their homes. That’s because a contractor’s tools and machinery 

are “used in, or to be used in” extraction wherever they are. Id. 

§ 802(h)(1)(C). 

Such absurd results are not required by the Act’s text. 

Reading the definition of “mine” in context shows that an item 

listed in subsection (C) must be located at an extraction site or 

a processing plant to count as a “mine” under the Act. 

B. Processing Plants Fall Within the Geographic Limits

The Commission and the Sixth Circuit both held, as I 

would, that the Act has a geographic limit. But they interpreted 

that limit to cover only extraction sites. I part company with 

them there. Textual clues suggest that the Act covers both extraction sites (where ore is dug out of the ground) and processing plants (where ore is made into a usable product). 

In Maxxim Rebuild, the Sixth Circuit held that “facilities 

and equipment” count as “mines” under the Act only “if they 

are in or adjacent to — in essence part of” an extraction site. 

848 F.3d at 740. The court reasoned that the list in subsection(C) reads as if the “author went to a mine and wrote down 

everything he saw in, around, under, above, and next to the 

mine.” Id. The Commission adopted the Sixth Circuit’s interpretation in its decision in this case. 

But subsection (C)’s list reads more like the “author went 

to a mine [and a processing plant] and wrote down everything 
9

he saw.” Id. That’s because three items on the list — “impoundments, retention dams, and tailings ponds” — are associated with coal processing, not coal extraction. 30 U.S.C. 

§ 802(h)(1)(C); see supra note 2. 

The rest of § 802(h)(1)(C) confirms that processing plants 

are included in the Act’s geographic sweep. Any item in the 

list counts as a “mine” if it is “used in, or to be used in . . . the 

work of preparing coal.” 30 U.S.C. § 802(h)(1)(C) (emphasis 

added). And the list ends by expressly stating that a “mine” 

“includes custom coal preparation facilities.” Id.

Plus, because many preparation plants are not located at 

extraction sites, the Sixth Circuit’s reading would produce an 

odd regulatory checkerboard. Some processing plants would 

be covered and others not, depending on how close they are to 

an extraction site. See Standards of Performance for Coal 

Preparation and Processing Plants, 74 Fed. Reg. 51,950, 

51,961 (Oct. 8, 2009) (noting that coal-preparation plants may 

be at “mine sites” or other “industrial sites”). That outcome is 

hard to square with Congress’s express view that “coal preparation facilities” are covered by the Act. 30 U.S.C. 

§ 802(h)(1)(C). 

Finally, interpreting § 802(h)(1)(C) to cover processing 

plants avoids surplusage. If subsection (C) were limited to 

items at an extraction site, it would largely collapse into subsection (A), which covers “area[s] of land from which minerals 

are extracted.” Id. But reading subsection (C) to include processing plants gives it a distinct role in the statutory scheme.

4

4 My interpretation is consistent with precedent. Cf. Maj. Op. 19-20. 

To repeat, I understand the items listed in § 801(h)(1)(C) to count as 

“mines” if they are located either at an extraction site (where mining 
10

III. Remand to the Commission is Unwarranted

Though I read the Mine Act’s definition of “mine” more 

narrowly than the Commission, I agree with its bottom-line 

conclusion. KC’s truck repair shop is not a “mine” under the 

Act because it is not at an extraction site or processing plant. 

So I would deny the Secretary’s petition for review. See Calcutt v. FDIC, 143 S. Ct. 1317, 1321 (2023) (we may affirm an 

agency, despite disagreeing with its reasoning, if the agency 

“was required to take [the] action” at issue (cleaned up)). 

Today’s majority takes a different tack. It first decides that 

the statute is ambiguous. Then, it remands to the agency to let 

the Secretary have a crack at interpreting it. Presumably, once 

the case comes back up on review, this court will defer under 

Chevron to the Secretary’s interpretation of the now-ambiguous statute — at least if it’s reasonable. See Chevron v. Natural 

Resources Defense Council, 467 U.S. 837 (1984); Secretary of 

Labor v. National Cement, 494 F.3d 1066, 1068 (D.C. Cir. 

2007) (remanding to let the Secretary interpret an ambiguous 

statute). 

occurs) or at a processing plant (where ore is turned into a usable 

product). So like National Cement II, I would not limit the Act’s 

reach to “the actual site where mining occurs.” Secretary of Labor 

v. National Cement Co. of California, Inc., 573 F.3d 788, 791 (D.C. 

Cir. 2009). And like Donovan, I would consider a processing plant 

“adjacent to a quarry” to be a “mine.” Donovan v. Carolina Stalite 

Co., 734 F.2d 1547, 1552 (D.C. Cir. 1984). As for whether National 

Cement I, 494 F.3d 1066, 1076 (D.C. Cir. 2007), means that “the 

Secretary should ‘confront’ the breadth and ambiguity of the Act” 

before a court may interpret it, Maj. Op. 20, “go take a look at the 

decision,” Andy Warhol Foundation for the Visual Arts, Inc. v. Goldsmith, 143 S. Ct. 1258, 1293 n.2 (2023) (Kagan, J., dissenting) (“I’ll 

take my chances on readers’ good judgment”). 
11

But that approach too readily relinquishes this Court’s 

duty to “decide all relevant questions of law” and to “interpret . . . statutory provisions.” 5 U.S.C. § 706. Deference under Chevron is appropriate only in those rare cases when “employing traditional tools of statutory construction” leaves a 

court “unable to discern Congress’s meaning.” SAS Institute 

Inc. v. Iancu, 138 S. Ct. 1348, 1358 (2018) (quoting Chevron, 

467 U.S. at 843 n.9). And even then, a court must satisfy itself 

that Congress meant to leave a “gap for the agency to fill” using 

its expertise. Chevron, 467 U.S. at 843.

That is not this case. As the parties agree, the meaning of 

the Mine Act depends on principles of statutory interpretation — not an exercise of policymaking discretion by the Secretary. Thus, the Commission interpreted the Act using “the 

traditional tools of statutory construction.” JA 161. And the 

Secretary’s opening brief acknowledged that “[t]he text is all 

that is necessary to divine the meaning of what constitutes a 

mine.” Pet. Br. 17. At argument, the Secretary reiterated: 

“[T]he statute is unambiguous. The Secretary is not asking this 

Court for deference. The Secretary is simply asking that this 

Court read the plain meaning of the statute, you know, as the 

Secretary does.” Oral Arg. Tr. 39.

In those circumstances, deference is inappropriate. When 

the “executive branch . . . ask[s] the court to do what courts 

usually do in statutory interpretation disputes [and] supply its 

best independent judgment about what the law means,” courts 

should not “place[] an uninvited thumb on the scale in favor of 

the government.” Guedes v. Bureau of Alcohol, Tobacco, Firearms & Explosives, 140 S. Ct. 789, 790 (2020) (Gorsuch, J., 

concurring in denial of certiorari); see also HollyFrontier 

Cheyenne Refining, LLC v. Renewable Fuels Association, 141 
12

S. Ct. 2172, 2180 (2021) (refusing to defer when “the government [did] not invok[e] Chevron”). 

Indeed, the Secretary’s shifting and self-serving interpretations of the Mine Act show just how inappropriate remand is 

here. When KC Transport first contested its citations before 

the ALJ, the Secretary insisted that he had jurisdiction because 

“each truck independently constituted a ‘mine’ ” under the Act. 

JA 156. After the ALJ rejected that argument — in his view, 

calling trucks “rolling mines” was “absurd” — the Secretary 

tweaked his position, now contending that KC’s truck-repair 

facility is a “mine.” Id.; Pet. Br. 17. Today’s remand gives the 

Secretary a third bite at the apple. 

What’s the upshot? A small trucking business is forced 

once more to fight a moving target. “While it is true enough . . .

that one who deals with the Government may need to turn 

square corners he need not turn them twice” — let alone three 

times. United States v. Winstar Corp., 518 U.S. 839, 922

(1996) (Scalia, J., concurring) (cleaned up).

Because I agree with the parties that this case can be resolved using the traditional tools of statutory interpretation, I 

would do just that. 

* * *

To count as a “mine” under the Mine Act, a “facility” like 

KC’s shop must be located at an extraction site or a processing 

plant. KC’s shop is not. So the Administration lacks jurisdiction over it. 

Because the majority disagrees, I respectfully dissent.