Opinion for the court filed by Circuit Judge HENDERSON.
Dissenting opinion filed by Circuit Judge ROGERS.
KAREN LECRAFT HENDERSON, Circuit Judge:The Secretary of Labor (Secretary) petitions for review of a decision of the Federal Mine Safety and Health Review Commission (FMSHRC or Commission) which reversed the decision of the administrative law judge (ALJ). The ALJ upheld the jurisdiction of the Mine Safety and Health Administration (MSHA) to issue a citation to the National Cement Co. of California, Inc. (National Cement) for failing to install guardrails or berms along a road National Cement uses to access its cement processing plant (Access Road) pursuant to a nonexclusive right-of-way grant from National Cement’s lessor, Tejón Ranchcorp (Tejón). Section 4 of the Mine Safety and Health Act (Mine Act or Act) provides that “[e]ach coal or other mine ... shall be subject to the provisions of this chapter.” 30 U.S.C. § 803. Section 3(h)(1) of the Act defines the term “coal or other mine” to include “(A) an area of land from which minerals are extracted in nonliquid form or, if in liquid form, are extracted with workers underground[or] (B) private ways and roads appurtenant to such area.” 30 U.S.C. § 802(h)(1). The ALJ concluded that the Access Road is a “mine” under section 3(h)(1)(B) — so as to come within the jurisdiction of MSHA — because, under the unambiguous language of section 3(h)(1)(A) and the undisputed facts, it is both “private” and “appurtenant to” National Cement’s Lebec Cement Plant, which is undisputedly a “mine” under section 3(h)(1)(A). Nat’l Cement Co. v. Sec’y of Labor, 27 F.M.S.H.R.C. 84 (2005) (ALJ Dec.). The FMSHRC reversed the ALJ, concluding that, although the road met the two unambiguous statutory criteria, the *1069Congress did not intend such a road to be classified as a mine subject to Mine Act jurisdiction because this classification will yield “absurd results.” Sec’y of Labor v. Nat’l Cement, 27 F.M.S.H.R.C. 721 (2005) (FMSHRC Dec.); see In re Trans Alaska Pipeline Rate Cases, 436 U.S. 631, 643, 98 S.Ct. 2053, 56 L.Ed.2d 591 (1978) (“This Court, in interpreting the words of a statute, has ‘some scope for adopting a restricted rather than a literal or usual meaning of its words where acceptance of that meaning would lead to absurd results (quoting Comm’r v. Brown, 880 U.S. 563, 571, 85 S.Ct. 1162, 14 L.Ed.2d 75 (1965)) (internal quotation omitted)). Because we conclude that the language of section 3(h)(1)(B) is ambiguous, we vacate the Commission’s decision and remand for the Secretary to interpret the statute’s ambiguous language.
I.
The material facts are not disputed. See Joint Stipulations (FMSHRC Docket No. WEST 2004-182-RM filed Nov. 17, 2004) (Joint Appendix (JA) 7) (Stip.). The Access Road runs across Tejon’s 27,000-acre ranch (Ranch), near the town of Le-bec in southern California. National Cement operates a cement processing plant on leased property within the Ranch, extracting minerals such as limestone, shale and silica from quarries and processing them with other trucked-in materials to produce Portland cement for sale. National Cement is not the only commercial entity that conducts business on the Ranch and uses the Access Road. Tejón and several of its other lessees also use the Access Road in the course of their respective business, as set out below.
The cement processing plant property, which consists of about 5,000 acres, was initially leased, with easement rights over the Access Road, to Pacific Western Industries, Inc. (Pacific Western) in 1966 for three successive 20-year terms and a final 19-year term. Cement Manufacturing Plant Lease (Lease) at 3^4 (JA 41-42). The lease and easement rights were later assigned to National Cement. Under a “Road Easement Deed” filed October 13, 1965, National Cement has “a non-exclusive right-of-way and easement for the purpose of constructing, reconstructing, altering, maintaining, repairing and using a road upon, over and across” a sixty foot-wide strip of land “for use and enjoyment by [National Cement] in connection with the construction and operation on [Tejon’s] land of a plant or plants for the processing and manufacture of portland cement and related by-products pursuant to lease terms between [Tejón] and [National Cement]” for the duration of the lease. Road Easement Deed at 1 (JA 29). Under the deed, Tejón “reserves for itself, its successors and/or assigns, the right to use and cross over said road and the right to grant to others easements in proximity to, crossing or overlapping the right of way and easement [t]herein granted provided such other easements shall not materially interfere with the use and enjoyment of the right of way and easement [t]herein granted.” Id. Road maintenance is governed by the 1966 lease which provides: “Lessee [National Cement] and the other grantees, if any, of joint-use easements and rights of way, pro rata in accordance with their respective use thereof, shall maintain' all such easements and rights of way in such condition as necessary for use thereof by Lessee in the usual conduct of its business.” Lease at 18 (JA 56).
Pacific Western developed the Access Road in the mid-1960s from an existing network of dirt roads on the Ranch. In the early 1970s, the California Department of Water Resources (DWR) constructed an aqueduct across the Ranch” with a bridge running over it where it intersects the Access Road. DWR then realigned the Access Road to traverse the bridge. Today *1070the Access Road is a paved 4.3-mile, two-lane road running north from State Route 138 to the cement plant. The Access Road’s use is restricted to “Tejon’s employees, vendors, contractors, lessees, licensees and visitors; National Cement’s employees, vendors, contractors and visitors; and those persons so authorized by the State of California.” Stip. ¶ 21 (JA 11). Signs indicating the restricted access are posted at the intersection with State Route 138 and along the initial segment of the road leading to the cement plant. Fencing, which encloses ranch land, runs along either side of the road, with gates located at various points opening onto dirt roads, trails and livestock corrals. Tejón maintains locks on most of the gates. None of the gates is used by National Cement, which has its own gate and guardhouse at the north end of the Access Road in front of the cement plant.1
The Access Road provides the only vehicular access to the cement plant. While “[t]he majority of traffic on the road is for cement-plant-related purposes,” id. ¶ 38 (JA 16),2 the road is also used by (1) Tejon’s ranch management staff, which travels it two to three times per month; (2) the Centennial Livestock Company, which leases 200,000 acres in the southern part of the Ranch where it maintains 7,000-9,000 head of cattle that are rotated among various fields every 6 months — its employees make about 300 round trips on the road annually; (3) customers of Te-jon’s “Film Department” which contracts with entertainment production companies, commercial photographers and others to provide locations on the Ranch for filming; (4) patrons of Tejon’s hunting program who use the road to access hunting areas (sometimes with Tejón guides) during 11 months of the year; (5) participants in Tejon’s “Explorer Program” who pay an annual fee to explore and camp on the Ranch from February through August each year; (6) Tejón security personnel who make daily rounds; (7) consultants performing work on a planned 12,000-acre commercial and residential development, which Tejón hopes to begin constructing in 2009 and which will use the Access Road both during construction and after completion; (8) Federal Aviation Administration agents who use the road for access to a communication tower located on the Ranch; (9) utility agents who use the road for access to transmission lines and related facilities; and (10) DWR which uses the road to access its aqueduct and bridge. Id. ¶¶ 45-66; 33 (JA 17-24, 15).
Since the mine’s inception, National Cement (and its predecessor cement plant operators) “have always maintained and kept in usable condition the road,” without seeking permission of Tejón. Id. ¶¶ 35-37 (JA 16). In November 2003, for example, National Cement at its own expense resurfaced, sealed and restriped the road and installed speed bumps and speed limit *1071signs. Id. ¶ 36 (JA 16). DWR, however, maintains “the bridge and its approaches” and National Cement “does not perform any construction or maintenance on this part of the road.” Id. ¶ 31 (JA 15). DWR has installed “speed bumps and related warning signs on the road in both directions at the approaches to the bridge.” Id. ¶ 34 (JA 15).
In 1992, a MSHA inspector cited National Cement for violating 30 C.F.R. § 56.9300(a), which requires: “Berms or guardrails shall be provided and maintained on the banks of roadways where a drop-off exists of sufficient grade or depth to cause a vehicle to overturn or endanger persons in equipment.”3 See JA 155. On April 9, 1992, MSHA vacated the citation through the following notice:
This action is to “vacate” this citation since it was issued in error.
The main entrance roadway was from a public highway to the mine site office traveled by the company and public to reach the mine property.
At the mine site near the main office where mine site activities begin was a posted guard shack indicating the restrictions and the actual activities of the mining operation.
The main entrance from the main public highway was leased by the mine operator but used/traveled by various other personnel and the public — once arriving at mine property signs were posted that the mine office must be contacted prior to entering the work sites.
The mine operator had no control over personnel using the entrance roadway until they arrived at the mine site office — (no security-locked gate at entrance off public highway).
Id. at 156.
On February 4, 2003, a MSHA inspector issued a citation (No. 6351224) to National Cement because the Access Road contained “faded and missing delineators for the entire distance of the haulway” in violation of 30 C.F.R. § 56.9300(d)(3).4 Id. at 157. During a routine review of the citation, MSHA’s district office determined that the inspector incorrectly cited National Cement because 30 C.F.R. § 56.9300(d)(3) applies to “elevated roadways” that “are infrequently traveled and used only by service or maintenance vehicles.” See ALJ Dec., 27 F.M.S.H.R.C. at 97. Accordingly, on February 13, 2003, Citation No. 6351224 was vacated and a new citation (No. 6351230) was issued for failing to install berms or guardrails in violation of 30 C.F.R. § 56.9300(a). The citation stated:
The primary access road to the plant had no guard rails or berms to protect vehicles and persons from going over the edge of the road. There are drop off[s] all along the highway ranging up *1072to approximately 25 feet where a vehicle could easily roll over. The road is used extensively by large over the highway trucks, miner’s vehicles, and various other vehicles. The two lane road without berms or guard rails presents a hazard, especially during inclement weather where the possibility of sliding and crashing may be prevalent.
JA 160.5
On April 14, 2003, after National Cement brought to MSHA’s attention the vacatur of the 1992 citation, the MSHA inspector lowered the citation’s negligence level from “Moderate” to “Low” because “[¡Information ... indicated that a previously issued citation for this condition was vacated, therefore the company’s negligence was less than originally evaluated.” Id. at 161. The MSHA District Manager concluded that MSHA had jurisdiction over the road but nonetheless on November 17, 2003 had the notice “vacated without prejudice due to inadequate notice that the road in question was subject to the Agency’s jurisdiction.” Id. at 162.
On December 16, 2003, the MSHA District Manager sent National Cement a letter informing it that MSHA considered the road subject to MSHA jurisdiction:
This letter is to inform you that MSHA has carefully reviewed the facts regarding the Wayne Hand Road which is located between National Cement Company’s Lebec Plant, and Highway 138. The Mine Safety and Health Act Section 3(h)(1)(B) specifically includes “private ways and roads appurtenant to” mines, as “mines” subject to MSHA jurisdiction. MSHA, therefore, examines all pertinent facts to determine whether such roads are to be considered as part of a mine. Here, MSHA has determined that it has jurisdiction over the Wayne Hand Road leading from Highway 138 to the Lebec Plant. This jurisdiction is based on our finding that National Cement Company maintains this road, that it holds an easement on this road and that this road is the sole means of egress to and from the mine. It also appears that traffic to and from the Lebec Plant constitutes the vast majority of traffic along this road.
National Cement Company is hereby put on notice that conditions which violate applicable MSHA regulations with respect to the road shall be subject to MSHA’s enforcement authority, effective immediately.
Id. at 163. Accordingly, on February 9, 2004, a MSHA inspector issued National Cement the subject citation (No. 6361036) for violating 30 C.F.R. § 56.9300(a). The citation reads:
The mine operator failed to provide berms and guardrails on the banks of the primary access road to the Lebec Cement Plant. There were drop offs along the roadway ranging from 6 ft. [t]o approximately 25 ft. and sufficient to cause a vehicle to overturn or endanger persons in equipment. The roadway was used extensively by large over-the-road trucks, delivery vehicles, and personal vehicles of mine personnel and vendors. The l[a]ck of berms or guardrails on the two lane road presented a hazard particularly during inclement weather when vehicles could be expected to slide and potentially become involved in accidents.
JA 164. National Cement filed a Notice of Contest of the citation and Tejón intervened in support of National Cement.
On cross-motions by MSHA and National Cement for summary decision on the *1073issue of Mine Act jurisdiction, the ALJ ruled in MSHA’s favor in a decision dated January 12, 2005. Nat’l Cement Co. v. Sec’y of Labor, 27 F.M.S.H.R.C. 84 (2005). The ALJ concluded that the access road is a “mine” under the plain language of section 3(h)(1) of the Mine Act, 30 U.S.C. § 802(h)(1), and rejected National Cement’s argument that “the circumstances of this case create ambiguity.” Id. at 99. The ALJ then directed the parties to advise him within 30 days whether they had reached a settlement or wished to proceed to a hearing on the merits of the citation.
Upon motion filed by National Cement on November 17, 2005, the FMSHRC vacated the ALJ’s decision, concluding that under the plain meaning of section 3(h)(1), the entire Access Road cannot be characterized as a “mine” under the Mine Act because to do so would violate the structure of the Act and produce “absurd results.” Sec’y of Labor v. Nat’l Cement, 27 F.M.S.H.R.C. 721 (2005). The Commission “h[e]ld instead that only such portion of the access road over which National Cement and its customers have exclusive use can be considered an appurtenant road” and remanded the matter to the ALJ to establish the parameters of the specified portion. Id. at 735. The Secretary filed a petition for review of the Commission’s decision on March 17, 2006.6
II.
On review, “the Secretary’s interpretation of the law must ‘ “be given weight by both the Commission and the courts.” ’ ” Sec’y of Labor v. Excel Mining, LLC, 334 F.3d 1, 5-6 (D.C.Cir.2003) (quoting Sec’y of Labor v. Cannelton Indus., Inc., 867 F.2d 1432, 1435 (D.C.Cir.1989) (quoting S.Rep. No. 95-181, at 49 (1977), U.S.Code Cong. & Admin.News 1977, pp. 3401, 3448)). “When, as here, ‘the Secretary and the Commission divide, 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, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984).’ ” Id. at 6 (quoting Cannelton Indus., 867 F.2d at 1435 (alterations in original) (parallel citation omitted)). “Moreover, in the statutory scheme of the Mine Act, ‘ “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 ... health and safety standard,’ ” and is therefore deserving of deference.” Id. (quoting RAG Cumberland Res. LP v. FMSHRC, 272 F.3d 590, 596 n. 9 (D.C.Cir.2001) (quoting Martin v. Occupational Safety & Health Review Comm’n, 499 U.S. 144, 157, 111 S.Ct. 1171, 113 L.Ed.2d 117 (1991))). In this case, however, we do not accord the Secretary’s litigating position Chevron deference because she incorrectly treated the statute as unambiguous and interpreted it accordingly. See 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.” ’ ” (quoting PDK Labs., Inc. v. DEA, 362 F.3d 786, 798 (D.C.Cir.2004) (quoting Arizona v. Thompson, 281 F.8d 248, 254 (D.C.Cir.2002)))).
Under step one of Chevron, we “ask ‘whether Congress has directly spoken to the precise question at issue,’ in which case we ‘must give effect to the unambiguously expressed intent of Congress.’ ” Bluewater Network v. EPA, 372 F.3d 404, 410 (D.C.Cir.2004) (quoting Chevron, 467 U.S. at 842-43, 104 S.Ct. *10742778). “If the ‘statute is silent or ambiguous with respect to the specific issue,’ however, we move to the second step and defer to the agency’s interpretation as long as it is ‘based on a permissible construction of the statute.’ ” Id. (quoting Chevron, 467 U.S. at 843, 104 S.Ct. 2778). Before the Commission, as here, the Secretary has relied on the plain meaning of the statute, viewing its language as unambiguous. See FMSHRC Dec., 27 F.M.S.H.R.C. at 726 (“The Secretary argues for affirmance of the judge’s decision because the definition of ‘coal or other mine’ plainly includes a road such as the one at issue.” (emphasis added)); see also id. at 728 (rejecting “literal interpretation of the specific words used in section 3(h)(1)(B) offered by the Secretary”); Sec’y’s Br. at 19-33 (asserting road is “mine” under section 3(h)(l)(B)’s “plain meaning”).7 The statute has no plain meaning, however, because section 3(h)(l)(B)’s language is, in our view, ambiguous.
As explained earlier, section 3(h)(1)(B) establishes that a road is a “mine” subject to MSHA’s jurisdiction if it meets two criteria: it must be (1) “private” and (2) “appurtenant to” an “area” that constitutes a “coal or other mine” under section 3(h)(1)(A). 30 U.S.C. § 802(h)(1)(B). The FMSHRC, following the lead of the ALJ and with the approval of the parties, relied on the dictionary definition of “private” as “intended for or restricted to the use of a particular person or group or class of persons: not freely available to the public.” Webster’s Third New Int’l Dictionary, 1804-05 (1993) (Webster’s). Under this definition, the term may be construed, as the Secretary argued and the Commission concluded, to mean restricted to the use of “a particular ... group or class of persons” — in this case, all of the grantees to whom Tejón may grant a right of way— and their invitees — which, as it turns out, are many and varied, see supra p. [5], Under the same definition, however, “private” may be construed more narrowly to mean restricted to the use of “a particular person” such as National Cement. See also Webster’s at 1805 (setting out alternative definition “belonging to or concerning an individual person, company, or interest”). Given these alternative meanings, the word “private” is, in our view, ambiguous.
The term “appurtenant to” is also ambiguous under the dictionary definition applied by both the ALJ and the Commission. “Appurtenant” is defined as “ ‘a: annexed or belonging legally to some more important thing (a right-of-way- — -to land or buildings); b: incident to and passing in possession with real estate — used of certain profits or easements.’ ” See FMSHRC Dec., 27 F.M.S.H.R.C. at 728 (quoting Webster’s at 107). Under this definition, the phrase may be construed to encompass a road such as the Access Road because it is subject to a transferable right of way benefitting the mine lessee. Or, again, the term might have been used in a narrower sense, as suggested by the definitional language “annexed or belonging legally to,” to mean dedicated exclusively to the use of the mine. See Webster’s at 87 (defining “annex” as “to join in a closely united but subordinate capacity: take possession or control of: assume rights or jurisdiction over”); id. at 201 (defining “belong” as “to be the property of a person or thing”).
In sum, both of the relevant statutory terms are ambiguous and the Secretary therefore erroneously interpreted them as bearing a plain meaning. In the event of such ambiguity, “ ‘it is incumbent *1075upon the agency not to rest simply on its parsing of the statutory language’ — ‘[i]t must bring its experience and expertise to bear in light of competing interests at stake.’ ” Peter Pan, 471 F.3d at 1354 (quoting PDK Labs., Inc., 362 F.3d at 797-98 (citing Chevron, 467 U.S. at 865-66, 104 S.Ct. 2778) (alteration in original)). If the agency has not done so, “ ‘at this stage it is not for the court “to choose between competing meanings.” ’ ” Id. (quoting PDK Labs., Inc., 362 F.3d at 798 (quoting Alarm Indus. Commc’ns Comm. v. FCC, 131 F.3d 1066, 1072 (D.C.Cir.1997))). “Chevron step 2 deference is reserved for those instances when an agency recognizes that the Congress’s intent is not plain from the statute’s face.” Id. Because the Secretary did not recognize the ambiguities inherent in the statutory terms, we do not defer to her plain meaning interpretation but instead remand for her to treat the statutory language as ambiguous. See id. at 1352. We recognize that we do not ordinarily remand a case with instructions regarding the decisionmaking process of a litigant. As we have demonstrated above, however, it is well established that the Congress intended us to afford Chevron deference to the Secretary — a litigant below — not the Commission — the adjudicator below. Coupling that principle with the principle drawn from Peter Pan and PDK Labs, Inc., requiring a Chevron-worthy agency to recognize ambiguity, we are left with no other rational result. Accordingly, we follow that course of action.
Both National Cement and Tejón identified “absurd results” they claimed would arise from the Secretary’s plain meaning interpretation of the statute — because of National Cement’s status as a non-exclusive right-of-way grantee, with only limited control or authority over the Access Road or its users outside the cement plant premises. These are not frivolous concerns.
First, it is questionable that National Cement, as a “nonexclusive” right-of-way grantee, has the authority to alter the road as the Secretary requires — notwithstanding National Cement has sua sponte, without interference, previously performed routine maintenance and made minor alterations (e.g., installing speed bumps and speed limit signs). National Cement’s easement is subject to the right Tejón reserved to itself to use the road — and to grant others the right to use it — along with National Cement. Alteration of the Access Road might interfere with the others’ right to use it and Tejon’s right as property owner to control it. In addition, it is undisputed that National Cement lacks authority to make any changes to the portion of the bridge approaching or crossing the aqueduct as DWR has the exclusive right to maintain this portion of the road and has in the past installed speed bumps and signs. Stip. ¶ 34 (JA 25).
Second, under the Secretary’s interpretation, National Cement as the mine “operator” would be required to assume responsibility for all road users, including those over whom it has no authority and with whom it has no business connection whatsoever. For example, as “operator” of the “mine,” National Cement would be required to (1) comply with a withdrawal order of the Secretary requiring it to cause “all persons,” including invitees of Tejón and other right-of-way grantees, to withdraw from a specified area of the Access Road, 30 U.S.C. § 814(b), (d)(l)-(2), (e);8 (2) “[i]n the event of any accident occurring [on the road] ... notify the Secretary thereof and ... take appropriate measures to prevent the destruction of any evidence *1076which would assist in investigating the cause or causes thereof,” id. § 813©; and (3) “provide site-specific hazard awareness training, as appropriate, to any person who is not a miner ... but is present [on the road],” 30 C.F.R. § 46.11(b). National Cement could thus be liable for violating the cited provisions notwithstanding it lacks authority to comply with them because it lacks control over all Access Road users. See FMSHRC Dec., 27 F.M.S.H.R.C. at 732 (“[0]n appeal the Secretary has reaffirmed her authority to hold National Cement strictly liable for all violations, including those committed by unrelated third parties. Thus, as National Cement fears, it appears that the Secretary would issue a citation for Mine Act violations committed by a user of the road who had no connection to National Cement’s operations.”) (internal citation omitted).
Third, because the Act defines a mine “operator” expansively to include “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), under the Secretary’s interpretation Mine Act jurisdiction would extend to Tejón as the “operator” (owner) of the Access Road and to any other party with right-of-way control over the Access Road notwithstanding the party lacks any relation whatsoever to the mine’s operations. Each of them could be liable as a mine operator for mine safety infractions occurring on the Access Road.9
The Secretary responds that she will, “as a matter of prosecutorial discretion,” refrain from citing “Tejón users whose conduct has no appreciable effect on the safety of National Cement miners.” Sec’y’s Br. at 39. This vague, open-ended (and unenforceable) representation offers scant comfort to the various road users who would be subject to liability under the Secretary’s expansive construction of Mine Act jurisdiction. In any event, the Mine Act itself does not authorize such prosecutorial discretion but mandates that a citation issue when its provisions or the regulations promulgated thereunder are violated by a party within Mine Act jurisdiction. See 30 U.S.C. § 814(a) (“If, upon inspection or investigation, the Secretary or his authorized representative believes that an operator of a coal or other mine subject to this chapter has violated this chapter, or any mandatory health or safety standard, rule, order, or regulation promulgated pursuant to this chapter, he shall, with reasonable promptness, issue a citation to the operator.” (emphasis added)).
These are problems the Secretary must confront on remand if she continues to interpret section 3(h)(1) to extend Mine Act jurisdiction over the entire Access Road. Although a statutory interpretation that is “employed in the course of an adjudication constitutes an ‘interpretative’ statement and as such is exempt from the APA notice and comment requirements,” nonetheless, under Chevron the Secretary must “offer a reasoned analysis” of her statutory reading. Orengo Caraballo v. Reich, 11 F.3d 186, 195, 193 (D.C.Cir.1993). Reasoned analysis requires that the words of the statute “ ‘be read in their context and with a view to their place in the overall statutory scheme.’” Ne. Md. Waste Disposal Auth. v. ERA 358 F.3d 936, 944-45 (D.C.Cir.2004) (quoting Davis v. Mich. Dep’t of Treasury, 489 U.S. 803, 809, 109 S.Ct. 1500, 103 L.Ed.2d 891 (1989)). Here, this means that the Secretary must address the concerns raised by National Cement and Tejón and harmonize her interpretation of section 3(h)(1)(B) *1077with the Mine Act’s overall enforcement of mine safety standards. Given that National Cement lacks control over the Access Road or those traveling upon it beyond the well-marked boundaries of the cement processing plant itself such harmony may be difficult to achieve. As the Sixth Circuit has observed, the reach of Mine Act jurisdiction under section 3(h)(1)(B) is not limitless:
Without some limitation on the meaning of “roads appurtenant to,” MSHA jurisdiction could conceivably extend to unfathomable lengths since any road appurtenant to a mine that connects to the outside world would necessarily run into yet other roads, thus becoming one contiguous road. Because of the potential reach of MSHA jurisdiction if the definition in § 802(h)(1)(B) is left unfettered, “private ways and roads” cannot simply mean “any road.” Otherwise, there could conceivably be no limit to MSHA jurisdiction, a result Congress clearly did not intend.
Bush & Burchett, Inc. v. Reich, 117 F.3d 932, 937 (6th Cir.1997).
Because the terms “private” and “appurtenant to” in section 3(h)(1)(B), 30 U.S.C. § 802(h)(1)(B), 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 of section 3(h)(1)(B), which addresses the problematic issues raised by National Cement and Tejón.
So ordered.
. Adjacent to the guardhouse is a sign advising:
ANYONE ENTERING THIS FACILITY MUST STOP AT THE FRONT OFFICE AND CHECK IN BEFORE PROCEEDING TO ANY OTHER LOCATION WITHIN THE PLANT.
EXCEPT NATIONAL CEMENT EMPLOYEES, DELIVERY WORKERS and OVER THE ROAD TRUCK DRIVERS. THIS INCLUDES, BUT IS NOT LIMITED TO VENDORS, SALESMEN, ■ CONTRACTORS, SERVICEMEN, AND VISITORS.
This is a Mine Safety and Health Administration, (MSHA) regulated site and as such requires all those who enter to comply with 30 Part 46 of the Code of Federal Regulations (CFR).
Stip. ¶ 27 (JA 14).
. That mining activity accounts for a "majority” of road use, as the parties stipulated, is not to say that it "dwarf[s]” road use, as the dissent asserts in its fifth "undisputed” fact, drawing on the ALJ’s characterization. Dissent at 1080 n. 2.
. The Secretary’s regulations define a “berm” as "a pile or mound of material along an elevated roadway capable of moderating or limiting the force of a vehicle in order to impede the vehicle’s passage over the bank of the roadway.” 30 C.F.R. § 56.2. The required berms or guardrails "shall be at least mid-axle height of the largest self-propelled mobile equipment which usually travels the roadway.” Id. § 56.9300(b).
. This regulation provides:
(d) Where elevated roadways are infrequently traveled and used only by service or maintenance vehicles, berms or guardrails are not required when all of the following are met:
(3) Delineators are installed along the perimeter of the elevated roadway so that, for both directions of travel, the reflective surfaces of at least three delineators along each elevated shoulder are always visible to the driver and spaced at intervals sufficient to indicate the edges and attitude of the roadway.
30 C.F.R. § 56.9300(d)(3).
. No one has suggested that the fencing along both sides of the road, which appears from photographs in the record to be strung wire, see, e.g., JA 132, 135, 142, is an adequate substitute for the required berms or guardrails.
. In a letter filed December 12, 2006, the FMSHRC informed the court it “w[ould] not file a brief' and “w[ould] not participate as an active litigant.”
. In her reply brief the Secretary argues for the first time that her interpretation is reasonable and is therefore due deference under Chevron step 2. See Reply Br. at 23-25.
. "[Pierson” is broadly defined in the Mine Act as "any individual, partnership, association, corporation, firm, subsidiary of a corporation, or other organization.” 30 U.S.C. § 802(f).
. In fact, the Secretary acknowledges that she would treat Tejón as an operator subject to Mine Act jurisdiction. See Sec’y's Br. at 37 n. 9; Reply Br. at 15-16.