PUBLISH UNITED STATES COURT OF APPEALS
FOR THE TENTH CIRCUIT

________________ _________________ CANYON FUEL COMPANY, LLC, Petitioner,

v. SECRETARY OF LABOR; FEDERAL MINE SAFETY AND HEALTH REVIEW COMMISSION, Respondents. No. 17-9541

________________ _________________ Petition for Review of an Order from the Federal Mine Safety and Health Review Commission (MSHR No. West 2015-635)

________________ _________________ Ralph Henry Moore, II (P atrick W. Dennison with him on the brie fs), Jackson Kelly PLLC, Pittsburgh, Pennsyl vania, for Petitioner. Emily C. Toler, Attorney (Nichola s C. Geale, Acting Solicitor o f Labor; April E. Nelson, Associate Solicitor; and Ali A. B eydoun, Counsel, Appellate Lit igation, with her on the brief), United States Department of Labor, Office of the Solici tor, Arlington, Virginia, for Respondents.

________________ _________________ Before MATHESON , PHILLIPS , and McHUGH , Circuit Judges.

________________ _________________ McHUGH , Circuit Judge.

________________ _________________ FILED United States Court of Appeals Tenth Circuit 

### July 10, 2018
Elisabeth A. Shumaker Clerk of Court2 Canyon Fuel operates the Sufco Mi ne, a coal mine located in Sev ier County, Utah. Under federal law, the mine must have two escapeways in t he event of an emergency: a primary escapeway a nd an alternate escapeway. An i nspector for the Mine Safety and Health Administr ation (“MSHA”) cited Canyon Fue l for a violation of this mine safety requirement . Canyon Fuel unsuccessfully con tested the citation before the federal agency and now petitions for judicial review of that decision. We affirm the Secretary of Labor’s i nterpretation of the regulatio n as requiring consideration of both above- and below-ground factors, but we v acate the citation because it is not supported by substantial evidence.
I. BACKGROUND A. Factual History Canyon Fuel’s Sufco Mine employs b etween eighty and ninety mine rs per shift. Canyon Fuel Co. v. Sec’y of L abor, Mine Safety & Health Admin. , 38 FMSHRC 2205, 2206 (2016) (“ Canyon Fuel I”). Approximately twent y of those miners are deployed to the two working secti ons of the mine relevant to th is appeal. Id. The primary escapeway from the mine e xits through the West Lease Po rtal, which is the main entrance to the mine and is accessible by road. Id. at 2207. Canyon Fuel installed the 4 East Fan Portal in 1991 and designated it as th e primary escapeway in
1992. Id. at 2210. Later, Canyon Fuel design ated the 4 East Fan Portal a s the alternate escapeway. Id. at 2210. The 4 East Fan Portal, unlike the West L ease Portal, opens onto a canyon ledge that is not accessible by road. Id. at 2207. For over twenty3 years, the 4 East Fan Portal rem ained as Canyon Fuel’s designat ed alternate escapeway, without objection from MSHA. Id. at 2214. In June 2014, Russell Riley, MSHA’ s District Manager for Coal D istrict 9, which includes the Sufco Mine, vis ited the mine to conduct an i nspection. Id. at 2206. Mr. Riley examined the es capeway map and noted that the p rimary escapeway exited through the West Lease Po rtal, while the alternate escap eway exited through the 4 East Fan Portal. Id. at 2207. Mr. Riley asked why other portals close to the working sections were not used fo r escapeways and was told ther e were no roads to those portals. Id. Upon further inquiry, Mr. Riley learned that the 4 East Fan Po rtal also lacked road access. Id. Mr. Riley expressed his con cerns about use of the 4 East Fan Portal as the alternate es capeway and, after considering se veral potential alternatives, suggested that Canyo n Fuel instead designate as t he alternate escapeway another route that paralleled th e primary escapeway and also ex ited from the West Lease Portal (the “West L ease Portal escapeway”). Id. at 2208. The 4 East Fan Portal escapeway and the West Lease Portal escapeway travel along the same path for the first part of the route. The two escapeways then diverge and ha ve significant differences which are relevant to this dispute. We now describe those differences in some detail.
1. The 4 East Fan Portal Escapeway The current alternate escapeway f or the Sufco Mine is the 4 Eas t Fan Portal

route. Id. at 2207. The distance from the 4 East Fan Portal to the deepes t point of penetration in the working sectio ns of the mine is 2.34 miles. Id. at 2212. The4 escapeway from that deepest pointto the 4 East Fan Portal has five overcasts, which are “ventilation control[s] that permit[] two air currents to c ross without mixing.” Appellant’s Br. at 8. The exist ence of an overcast is importantfor assessment of the feasibility of an esc apeway because the overcast creates “an ov erpass over an entry and must be climbed up and over to continue” along the escapewa y. Id. Miners typically use either a ramp or a staircase to cross overcasts a nd, therefore, escaping miners usually cannot drive over an overcast in a vehicle. As a result, the more overcasts in an escapeway, the mor e difficult the path out of t he mine. Such travel is further complicated if the miners are carrying an injured colle ague. The escapeway to the 4 East Fan P ortal also requires two Self C ontained Self Rescuer (“SCSR”) change-out sta tions. An SCSR is a breathing ap paratus designed to allow a miner to breathe clean oxygen in the event that the surrounding atmosphere is oxygen-deficient ( potentially due to a fire) or c ontains harmful gases (such as methane). SCSRs are i ntended to last one hour, dependi ng on the degree of physical exertion by the user o f the SCSR and the user’s physic al condition. When a miner exhausts an SCSR, the minerreplaces the em pty SCSR with a new one, either one being carried by the miner orone that is stored in a chang e-out station along the route. SCSR change-out require ments are based on MSHA criteria. See 30 C.F.R. § 75.1714-4(c). A greater numbe r of change-out stations general ly corresponds with a longer travel time out of a mine or greater difficulty of trave l. Another significant aspect of th e escapeway to the 4 East Fan P ortal is that it is located in return air, rather tha n intake air. Air that comes i nto the mine immediately5 prior to reaching the working s ections is known as “intake air. ” After air has been used in the working sections, th e air is known as “return air” and is transported out of the mine. Because intake air co mes from outside t he mine, it ma y not be contaminated with smoke or gase s in a mine emergency. Thus, min ers may not need to don an SCSR in intake air, a ssuming the ven tilation system i s still working. See Sec’y of Labor, Mine Safety & Health Admin. v. Canyon Fuel Co. , 39 FMSHRC 1578, 1594 n.14 (2017) (“ Canyon Fuel II”) (reversing commissioners) (if the ventilation system is not functi oning, miners may be “inundatedin smoke” and “require supplemental air”). As a result, it may be advantageou s to have an escapeway with intake air, r ather than return air. Once the miners successfully tra verse the escapeway, they will arrive at the 4 East Fan Portal, which exits to the surface on a “ledge” or she lf in the side of a cliff. Canyon Fuel I , 38 FMSHRC at 2207. The ledge i s approximately 200 feet long b y 50 feet wide and is located about 1 50 feet above the canyon floor. Several buildings on the ledge, including a storage shed, a backup generator, and th e 4 East Fan/Fan House, occupy approxima tely half the area. The fan and the moto r are inside the fan house, along with first aid a nd communication equipment. Id. at 2211. It is warm inside the fan house year r ound, if the fan is running. Id. The buildings include enough space, even in just the fa n house, to fit all twenty min ers who might need to use the escapeway. Id. There is no road to the 4 East Fan Portal. Id. at 2207, 2211. As a result, miners seeking medical assistance would need either to walk down a “gr adual” slope to an6 unpaved cattle trail that parall els the dry creek bed at the bo ttom of the canyon or to climb to the top of the canyon. Id. at 2211. Both options woul d prove difficult. The cattle trail from the bottom of the 4 East Fan Portal shelf to a gravel road is approximately four to five miles long, is only two feet wide, a nd would take approximately two hours to walk, if clear. Id. In winter, the trail may have eight to twelve inches of snowpack. Id. Alternatively, min ers exiting through the 4 East Fan Portal could climb to the plate au. That option would entail “tr avel[ing] 400 to 500 yards up a drainage area to get to the top.” Id. Once on top of the plateau, a Forest Service road is located nearby. Id. But the road is not plowe d during the winter, so there is no guarantee of medical a ssistance even if the miners made it to the top. Id. Canyon Fuel has not attempted it s proposed route to the top of the plateau, yet claims it would be difficult, but possi ble, to carry an injured miner on a stretcher to the top.
Id. Helicopter service to the 4 East Fan Portal is restricted. Id. at 2212. Although the shelf is not large enough to land a helicopter, it may be p ossible to lower a basket for aerial evacuation of the miner s in the event o f an emergenc y. Id. at 2209. But Intermountain Life Flight, the onl y provider Canyon Fuel identi fied, has imposed significant restricti ons on such flights. Id. at 2209, 2212. The “he licopters cannot fly in winds greater than 45 mph [o r] with less than three miles of visibility.” Id. at 2209. Furthermore, the helicopters do not fly at night, in rain, ice, sleet, fog, snow, or heavy cloud cover. Id. Thus, injured miners could remain stranded on the shelf until the morning or until the weather improved.7 2. The West Lease Portal Escapeway The escapeway proposed by MSHA is the West Lease Portal route. Id. at 2208. The distance from the deepest poi nt of penetration to the West Lease Portal is 5.88 miles, over 3.5 miles longer tha n the 4 East Fan Portal escapew ay. Id. at 2212. However, miners could drive roug hly two-thirds of the proposed route if Canyon Fuel staged vehicles in the escapeway. 1 Id. at 2208. The West Lease Portal escapeway has twelve overcasts a nd would require five SCSR chan ge-out stations. This route largely parallels the primary escapeway. Id. Unlike both the primary escapeway and the 4 East Fan Por tal escapeway, however, it incl udes “a number of
turns.” Id. at 2210. The route also includes about one hundred seals used to close off mined out areas, 2 which may increase the ha zard to escaping miners. Id. at 2213. With the exception of the first p art of the route, the West Lea se Portal escapeway is in intake air, 3 making the risk of smoke inha lation during an emergency

1 Staging vehicles means leaving ve hicles in the mine at a desig nated point in the escapeway. From the point of divergence of the 4 East Fan P ortal route and West Lease Portal route, miners woul d need to travel approximately t hirty-five “crosscuts” by foot. Mine operators develop cr osscuts to connect parallel e ntries into a coal seam and may use crosscuts as a proxy for location or distance. If C anyon Fuel staged vehicles at crosscut 176, miners could drive from there to cros scut 4. They would then need to walk a few m ore crosscuts to exit.

2 Depending on the barometric pre ssure in the atmosphere, the se als may ingas, in which gas leaves the mine into the sealed off area, or outga s, in which gas leaves the sealed off area into the mi ne. While the Sufco Mine does no t produce many harmful gases, the outgas may in clude a low level of oxygen, wh ich may increase the risk to miners traveling the route.

3 From the point of divergence of the two routes, the 4 East Fan Portal route and the West Lease Portal route are in return air for approxima tely thirty and eight8 unlikely. Id. at 2209. It would take approxima tely three hours to exit the m ine from the point of divergence from the 4 East Fan Portal escapeway by walking. Id. at 2212. 4 This time may be increased if a miner is injured, wearing an S CSR, or carrying another miner. Id. Additionally, the route may re quire refuge alternatives as miners may not be able to make it out of the mine due to the di stance and difficulty. The West Lease Portal route ends a t approximately the same loca tion as the primary escapeway; it has road access and medical transportation could be waiting for injured miners. Id. at 2208. The following map is based on G overnment Exhibits 2 and 16 and Canyon Fuel Exhibit 1B. It depicts the wo rking sections of the mine at the top, the 4 East Fan Portal on the right, and the We st Lease Portal at the bottom. See slip op. at *9.

crosscuts, respectivel y. The 4 East Fan Po rtal route is in actu al return air while the West Lease Portal route is in de signated return air, which is a ir that has not ventilated a working section but has only been marked by Canyon Fuel as re turned. The West Lease Portal route continues for another 200 crosscuts in intak e air. Thus, the additional distance in return airfor the 4 East Fan Portal rou te may be relatively short in comparison with the W est Lease Portal route.

4 While two-thirds of the route are drivable, the government pre sented no evidence of how long evacuatio n would take when driving.9 Primary Escapeway 4 East Fan Portal/West Lease Portal Shared Point of Divergence 4 East Fan Portal Escapeway West Lease Portal Escapeway Working Sections

Exit Exit10 B. Procedural History In March 2015, when Canyon Fuel had not changed its alternate e scapeway from the 4 East Fan Portal route to the West Lease Portal route , MSHA issued Citation No. 8483766 for a viola tion of 30 C.F.R. § 75.380(d)(5 ). That regulation requires that escapeways be “[l ]ocated to follow the most direc t, safe and practical route to the nearest mine openi ng suitable for the safe evacuat ion of miners.” 30 C.F.R. § 75.380(d)(5). The citat ion explained that Canyon Fuel was in violation of the regulation because the alterna te escapeway was not accessib le via a roadway for land-traveling vehicles. Canyon Fuel I , 38 FMSHRC at 2206. MSHA determined the violation was not of a significa nt and substantial nature, conc luded Canyon Fuel was moderately negligent, and pr oposed a penalty of $425. Id. Later, MSHA amended the citation to change the deficientcondition to not providing “a roadway for landtravelling vehicles to access [t he] area from the surface or an y dependable alternative evacuation methods,” but it left in place the determination of negligence and the proposed penalty. Joint App. at 111. Two months later, MSHA issued C anyon Fuel two additional citati ons. Canyon Fuel I , 38 FMSHRC at 2218, 2222. Cany on Fuel challenges one of these, Citation No. 8480766, in a separate proceeding. 5 That citation charges a violation of

5 After filing its notice to cont est the citations, but before a decision was issued, see infra , Canyon Fuel filed a petition fo r modification of 30 C.F.R. § 75.1713-1(b) pursuant to 30 U.S.C. § 811(c). In re Canyon Fuel Co. v. Mine Safety & Health Admin. , 2016-MSA-8 (ALJ May 23, 2017), available at https:// www.oalj.dol.gov/Decisions/ALJ/M SA/2016/In_re_CANYON_FUEL_11 30 C.F.R. § 75.1713-1(b), which r equires Canyon Fuel to “make a rrangements with an ambulance service, or otherw ise provide, for 24-hour emergen cy transportation for any person injured at the mine.” Canyon Fuel contested all three citations before an administrat ive law judge (“ALJ”). The ALJ affirmed Cita tion No. 8483766 (the violation o f § 75.380(d)(5), requiring the escapeway to be “[ l]ocated to follow the most dir ect, safe and practical route to the nearest mine openi ng suitable for the safe evacuat ion of miners”), vacated another citation, and mo dified Citation No. 8480766 (th e violation of § 75.1713-1(b), requiring 24-hou r emergency transportation). Canyon Fuel I , 38 FMSHRC at 2227. Canyon Fuel then filed a petition for discretio nary review of Citation No. 8483766 and Citation No. 8480766 with the Federal Mine Safety and Health Review Commission (“the Co mmission”). The Commission una nimously COMPANY__2016MSA00008_( MAY_23_2017)_113837_CADEC_SD.PDF. Under § 811(c): [T]he Secretary may modify the application of any mandatory saf ety standard . . . if the Secretary determines that an alternative method of achieving the result of such sta ndard exists which will at all times guarantee no less than the same measure of p rotection afforded the miners of such mine by such standard, or that the app lication of such standard to s uch mine will result in a diminution of safet y to the miners in such mine. Canyon Fuel proposed building a safehouse and a helipad at the 4 East Fan Portal shelf as a substitute f or the “24-hour emergency transpo rtation” requirement of 30 C.F.R. § 75.1713-1(b). Id. at 11–12. It also identified another helicopter operator, the Utah Department of Public Saf ety, that has fewer restrictio ns on flights than Intermountain Life Flight. Id. An administrative law j udge (“ALJ”) denied the petition, id. at 46, but the Assistant Secret ary of Labor vacated and remand ed to the ALJ “for additional factual dete rminations and reconsideration of legal determinations,” In re Canyon Fuel Co. v. Mine Safety & Health Admin. , 2016-MSA8 (Assistant Sec’y of Labor Nov. 21, 2017).12 affirmed Citation No. 8480766 (the violation of § 75.1713-1(b), requiring 24-hour emergency transportation). Canyon Fuel II , 39 FMSHRC at 1581–83. But the panel could not agree on Citation No. 8483766, the violation at issue here. Two commissioners voted to affirm t he violation (“affirming commiss ioners”) and two commissioners voted to reverse th e violation (“reversing commis sioners”). Id. at 1579. As such, the ALJ’s decisi on for Citation No. 8483766 stan ds as though affirmed. See Sec’y of Labor, Mine Safety & He alth Admin. v. Penn. Elec. Co. , 12 FMSHRC 1562, 1563-65 (1990). Canyon Fuel timely filed this Petition for Review, challenging only Citation
No. 8483766.

II. DISCUSSION Because the Commission vote split two-to-two, the ALJ’s opinion affirming the violation was left in place and we review the ALJ’s opinion

. Plateau Mining Corp. v. Fed. Mine Safety & Health Review Comm’n , 519 F.3d 1176, 1191 (10th Cir. 2008). In doing so, we review the ALJ’s legal conclusions de no vo and his factual findings under the substan tial evidence standard. Id. ; 30 U.S.C. § 816(a)(1). To establish a violation of 30 C.F.R. § 75.380(d)(5), MSHA must id entify a route that more closely com plies with the regulati on than the currently de signated route. Sec’y of Labor, Mine Safety & Health Admin. v. S. Ohio Coal Co. , 14 FMSHRC 1781, 1785 (1992) (discussing § 75.38 0(d)(5)’s predecessor). Canyon Fuel claims the ALJ impr operly considered conditions exi sting outside the mine in determining that designation of the 4 East Fan Portal a s the alternate escapeway13 violated regulation 75.380(d)(5 ). It further contends that evenif the ALJ were permitted to consider the conditions affec ting miners once they exited through the 4 East Fan Portal, any finding as to whethe r the West Lease Portal route, and not the 4 East Fan Portal route, was “the most dir ect, safe and practical route to the nearest mine opening suitable for the safe evacuation of miners” is unsupported by the record evidence. 30 C.F.R. § 75.380(d)(5). The Secret ary of Labor (“Secretary”) dis agrees, asserting that both underground and above- ground conditions are relevant to whether the mine opening is “suitable for the safe evacuation of miners.” Id. And the Secretary argues that the ALJ’s finding that the West Lease Port al route better meets the regul ation is adequately supported by the record evidence. We begin our analysis with the l egal question: whether MSHA mayconsider conditions existing above ground in considering whether Canyon Fuel violated 30 C.F.R. § 75.380(d)(5). We th en proceed to the factual question: whethe r substantial evidence supports the ALJ’s finding that the West Lease Portal route mor e closely complies with the regulation than the 4 East Fan Portal route. We conclude th at the regulation permits the Secretary to consider all o f the facts and circumstances af fecting the escapeway, including surface conditions faci ng miners upon exit from the m ine. But we vacate the citation because the ALJ’s factua l finding that the West Lease Portal route better meets the requirement that the escapewaybe the “most direct, safe an d practical route to the nearest mine opening suitable fo r the safe evacuation of miners ” than does the 4 East Fan Portal route is not supported by substantial evidence.14 A. Interpretation of the Regulation In interpreting the regulation, “ we apply the same rules we use to interpret
statutes.” Mitchell v. Comm’r , 775 F.3d 1243, 1249 (10th Cir. 2015). We examine the plain language of the regulation and give each word its ordinar y and customary meaning. Id. Thus, in determining the plain meaning of a regulation, we do not consider the regulatory histor y or anything outside the text. I f the language of the regulation is clear, we enforce the regulation in accordance wi th its plain meaning, giving no deference to a contrary interpretation by the Secreta ry. Id. On the other hand, where the regulation is amb iguous, “we defer to the [Secr etary]’s reasonable interpretations, even those advan ced in his legal brief, unless ‘plainly erroneous or inconsistent with the regulati ons,’ or there is any other ‘reas on to suspect that the interpretation does not reflect t he agency’s fair and considere d judgment on the matter in question.’” Id. (quoting Chase Bank USA, N.A. v. McCoy , 562 U.S. 195, 208, 209 (2011)). In making this determination, we may “look be yond the plain language, examining regulatory in tent and overall statutory con struction.” Qwest Corp. v. Colo. P ub. Utils. Comm’n , 656 F.3d 1093, 1099 (201 1) (internal quotation marks omitted). Finally, “a regul ation must be interpreted in s uch a way as to not conflict with the objective of its organic statute.” Time Warner Entm’t Co., L.P. v. Everest Midwest Licensee, L.L.C. , 381 F.3d 1039, 10 50 (10th Cir. 2004).
1. Plain Language Canyon Fuel and the Secretary each argue that the plain languag e of 30 C.F.R. § 75.380(d)(5) suppo rts their interpretation of the regulation. Canyon Fuel argues the text15 of the regulation “addresses the efficiency of the alternate es cape routes out of the mine for purposes of providing mine rs . . . quick and safe egress out of the mine.” Appellant’s Br. at 15. It does not, according to Canyon Fuel, “consider con ditions outside once evacuation of miners from underground has occurred.” Id. In turn, the Secretary argues that § 75.380(d)(5) includes “two distinct requirements: (1) es capeways must be ‘located to follow the most direct, safe and practical route to the near est mine opening,’ and (2) that mine opening must be ‘suita ble for the safe evacuation of miners.’” Appellee’s Br. at 25–26 (quoting 30 C.F.R. § 75.380 (d)(5)). According to the Secr etary, “[w]hether a mine opening is ‘suitable for the saf e evacuation of miners’ depends on whether, at that mine opening, miners are out of danger o r can be quickly and safely removed from danger—an analysis that must take into a ccount conditions both undergroun d and at the surface.” Id.
at 26. The regulation reads: (d) Each escapeway shall be—

. . . . (5) Located to follow the most direct, safe and practical route to the nearest mine opening suitable fo r the safe evacuation of miners

. . . . 30 C.F.R. § 75. 380(d)(5). The regulation does not define “evacu ation” or “suitable”; thus we interpret them to have thei r ordinary or dic tionary definiti ons. See Nat’l Credit Union
Admin. Bd. v. Nomura Home Equity Loan, Inc. , 764 F.3d 1199, 1227–28 (10th Cir. 2014). The definition of “evacuate” most relevant in this conte xt is: “[t]o remove . . . to safer surroundings.” Evacuate , Oxford English Dictiona ry, http://www.oed.com/view/ Entry/65161 (last visited June 25, 2018). Thus, “evacuation” as used in the regulation16 could mean either (1) removal from the interior of the mine to the mine opening or (2) removal from the mine opening t o another location. In turn, “su itable” is defined as “fitted for, adapted or appropriate to a person’s . . . needs . . . .” Suitable , Oxford English Dictionary, http://www.oed.com/v iew/Entry/193721 (last visited June 25, 2018). The definition of “suitable,” like th e definition of “evacuation,” does not dictate that either the Secretary’s or Canyon Fuel’s reading is plainly correct.

a. Does “suitable for the safe evacuati on of miners” modify the “route” or the “mine opening”? The Secretary argues “suitable for the safe evacuation of miner s” applies to the mine opening instead of the route. Contrarily, Canyon Fuel argu es that “suitable for the safe evacuation of miners” modi fies the route. In support of hi s position, the Secretary notes that principles of statuto ry construction, such as the “n earest reasonable referent canon” (sometimes called the la st antecedent rule), support his reading. Under this canon, “a limiting clause or phrase . . . sh ould ordinarilybe read as modifying only the noun or phrase that it immediately follows.” Barnhart v. Thomas , 540 U.S. 20, 26 (2003); United States v. Osage Wind, LLC , 871 F.3d 1078, 1091 n.11 (10th Cir. 2017), petition for cert. filed , 17-1237 (Mar. 6, 2018). Because the phrase “suitable for the safe evacuation of miners” immediately follows “mi ne opening,” the Secretary argue s that the “grammatically sound interpretati on” is that it modifies “mine opening” instead of “route.” Appellee’s Br. at 28. But this canon of construction is not mandatory nor is it alway s the most reasonable interpretation of a re gulation. Indeed, we have clas sified it as “merely an17 interpretive presumption based on the grammatical rule against misplaced modifiers.” Payless Shoesource, Inc. v. Travelers Cos. , 585 F.3d 1366, 1371 (10th Cir. 2009) (rejecting the application of the canon). And the Supreme Court has noted that the presumption “can assuredly be ove rcome by other indicia of mean ing.” Jama v. Immigration & Customs Enf’t , 543 U.S. 335, 355 (2005) (internal quotation marks omitted). “Given how co mmon misplaced modifiers are in daily us age, the Supreme Court has candidly acknowledged that ‘over the years, such indi cia have counseled us against invoking the rule (oftenunanimously) at least as many times as we have relied on it.’” Payless , 585 F.3d at 1371–72 (quoting Jama , 543 U.S. at 355 ). Thus, “while the rules of English grammar often a fford a valuable starting point to understanding a speaker’s meaning, they are violated so often by so many of us that they can hardly be safely relied upon as the end point of any analysis of . . . pl ain meaning.” Id. at 1372. We have also noted that “referentia l and qualifying words or phras es refer only to the last antecedent, unless contrary to th e apparent legislative intent. ” Seneca-Cayuga Tribe of Okla. v. Nat’l Indian Gaming Comm’n , 327 F.3d 1019, 1038 (1 0th Cir. 2003) (internal quotation marks omitted). So, wh ile the “nearest reasonable ref erent canon” provides one possible reading of the regulatio n, we are not bound by the grammatical principle, especially if it is contrary to the “apparent [regulatory] inte nt” of the regulation. The Secretary further argues that Canyon Fuel’s interpretation renders the phrase “suitable for the safe evacuatio n of miners” meaningless becaus e other standards and the other clause of § 75.380(d)(5) a lready require the escapeway ro utes to be “suitable for the safe evacuation of miners.” Becau se we should interpret the standard to give effect to18 each word and clause, see, e.g. , Bridger Coal Co./Pac. Minera ls, Inc. v. Dir., Office of Workers’ Comp. Programs, U.S. Dep’t of Labor , 927 F.2d 1150, 115 3 (10th Cir. 1991), the phrase must be read to modi fy the mine opening rather than the route. The Secretary contends that Canyon Fuel’s read ing of the standard renders the phrase superfluous—if the route is the “most direct, safe and practical,” then it wou ld also be suitable for “safe evacuation.” Thus, he argues, the phrase “suitable for the safe evacuation of miners” logically must modify the mine opening. But Canyon Fuel counter s that “suitable for the safe evacuation of miners” clari fies that the shortest route may not be proper if conditions inside the mine render it unsuitable. We are convinced that bot h positions are reasonable. The Secretary and Canyon Fuel each advance reasonable interpret ations of the text. The phrase “suitable for the safe evacuation of miners” m ight be intended to modify either the route or the mine opening. b. Are outside conditions considered in determining “suitability”? It is also not plain from the te xt of the regulation whether co nditions outside the mine may be considered in de termining “suitability.” If, as Canyon Fuel argues, the route must be “suitable for the safe evacuation of miners” to the surface, it is reasonable to conclude that conditions inside the mine, rather than conditions at the surface, are considered in dete rmining suitability. The Secreta ry disagrees and contends that, if the mine openi ng itself must be “suitable,” t hen it is reasonable to include conditions outside the m ine. Simply put, the language o f the regulation standing alone does not clearly indicate whether conditions out side the mine may be considered.19 Nor does looking to other regula tions in the section resolve th is ambiguity. To be sure, these subsections all deal with conditions inside the mine 6 and thus may suggest that (d)(5) also relates to conditions inside the mine. And subsection (e) of the escapeway standard, which sp ecifically provides requirement s for surface openings, is focused on surface conditions that may impact cond itions in the mine. 7 But nothing in subsection 75.380 (d)(5) precludes the analysis o f suitability from including an examination of cond itions on the surface affecting the miners’ safety upon exiting the mine. Further, as noted by the Secret ary, without some consideration of outside conditions, the regula tion could lead to an absurd result. For example, an escapeway could lead to a shelf with no sh elter and no exit, a shelf that is only two feet wide, or a cliff with no shelf at all. T he Secretary argues that under s uch circumstances, the

6 30 C.F.R. § 75. 380(d) reads: (d) Each escapeway shall be— (1) Maintained in a safe condition . . . ; (2) Clearly marked to show the r oute and direction of travel to the surface; (3) Maintained to at l east a height of 5 f eet from the mine flo or to the mine roof . . . ; (4) Maintained at leas t 6 feet wide . . . ; (5) Located to follow the most d irect, safe and practical route to the nearest mine opening suitable for the sa fe evacuation of miners; and (6) Provided with ladders, stai rways, ramps, or similar facilit ies where the escapeways cross over obstructions. (7) Provided with a continuous, durable directional lifeline orequivalent device that shall be— (i) Installed and maintained thr oughout the entir e length of ea ch escapeway . . . .

7 “Surface openings shall be adequa tely protected to prevent sur face fires, fumes, smoke, and flood water fro m entering the mine.” 30 C.F.R . § 75.380(e).20 escapeway would not lead to a “m ine opening suitable for the sa fe evacuation of miners.” It follows then, he con tinues, that any evaluation of the suitability of a mine opening must consider conditions both outside of the mine and u nderground. * * * Both Canyon Fuel and the Secretar y have advanced plausible inte rpretations of the regulation’s plain language. Thus , we agree with the ALJ that the regulation is ambiguous. Canyon Fuel I, 38 FMSHRC at 2214. “Suitable for the safe evacuation of miners” could modify either the “ route” or the “mine opening.” Additionally, whether conditions outside the mine may be considered in determining “s uitability” for the safe evacuation of miners is not cle ar from the text of the regulati on. 2. Deference to the Secretary Because the plain language of th e regulation is ambiguous, “we defer to the [Secretary]’s reasonable interp retations, even those advanced i n his legal brief, unless ‘plainly erroneous or inconsiste nt with the regulations,’ or th ere is any other ‘reason to suspect that the interpreta tion does not reflect the [Secret ary]’s fair and considered judgment on the matter in question.’” Mitchell , 775 F.3d at 1249 (quoting Chase
Bank , 562 U.S. at 208, 209). As discu ssed, the Secretary has interp reted the regulation to require the consid eration of two factors: 1) whet her the escapeway is “[l]ocated to follow the most d irect, safe and practical route to the nearest mine opening;” (practicality) and 2) w hether that “mine opening” is “suitable for the safe21 evacuation of miner s” (suitability). 8 30 C.F.R. § 75.380(d)(5). The Secretary has also indicated that whether the mine opening is “suitable for the sa fe evacuation of miners” takes into considerati on conditions both inside the min e and outside the mine. Having already concluded that t he Secretary’s interpretation is not precluded by the plain language of the stat ute, we next consider whether deference to the Secretary is inappropriate becaus e the Secretary’s “current int erpretation runs counter to the intent at the time of the regulation’s promulgation,” Gonzales v. Oregon , 546 U.S. 243, 258 (2006) (internal q uotation marks omitted). That i ntent may be determined, at least in part, bas ed on “the regul ation’s histor y, the agency’s contemporaneous explanation, and its consistently held interpre tive views.” Williamson v. Mazda Motor of Am., Inc. , 562 U.S. 323, 336 (2011); see Copar Pumice Co. v. Tidwell , 603 F.3d 780, 794–95 (10th Ci r. 2010) (determining whether “an alternative reading [other tha n that of the Secretary] is c ompelled . . . by other indications of the Secretary’s in tent at the time of the regula tion’s promulgation” by referencing the regulatory hist ory including re sponses to publi c comments). In addition, “a regulation must be in terpreted in such a way as to not conflict with the objective of its organic statute,” Time Warner , 381 F.3d at 1050, so a reading contrary to the governing statut e does not deserve deference. B ut “where there is an

8 For clarity, we refer to the fir st factor as an assessment of the practicality of the route and the second factoras the suitability of the mine opening. When referring to the comprehensive considerati on of both practicality of the route and suitability of the mine opening, we refer to the most acceptable escapeway—or acceptability.22 interpretation of an ambiguous re gulation which is reasonable a nd consistent with the statute, that interpretation is to be preferred.” Emery Mining Corp. v. Sec’y of Labor , 744 F.2d 1411, 1414 ( 10th Cir. 1984) (internal quotation marks omitted).

a. History of the regulation In 1977, Congress passed the Fede ral Mine Safety and Health Actto improve safety and health in the nation’ s mines. 30 U.S.C. § 801(a). As part of the statute, Congress created MSHA to act on be half of the Secretary of Labo r to promulgate safety and health standards, ins pect mines, issue citations, an d propose penalties for violations. Id. §§ 811(a), 813(a), 814(a), 814( d), 815(a), 820(a). Congress al so created the Commission to r eview the actions of MSHA. Id. § 823(a). ALJs hear contests of citations initiated by mine operators and conduct i nitial hearings, while the Commission has discretion to r eview the decisions of the AL Js. Id. § 823(d)(2)(A)(ii). Further revi ew by a federal court of appeal s is allowed as a matter of right. Id. § 816(a). The predecessor to the 1977 Act, t he Federal Coal Mine Health a nd Safety Act of 1969, required mine operators to maintain a primary and alte rnate escapeway, which must be separate and dis tinct. Pub. L. No. 91-173, § 317( f)(1), 83 Stat. 742, 788 (1969). Congress required two escapeways because, in an eme rgency, one escapeway may be inacce ssible or untraversable. “Mine fires, ex tensive collapse of roof, or similar occurrences may completely block the regular t ravelway . . . thus cutting off escape in an emergenc y unless an alternate route is provided to the23 surface.” S. Rep. No. 91-411, at 83 (1969). This requirement wa s retained in the 1977
Act: [A]t least two separate and distin ct travelable passageways . . . which are to be designated as escapew ays . . . shall be provided from each working section . . . and shall be maintained in safe condition and properly marked. . . . Escape f acilities approved by the Secret ary . . . , properly maintained and frequently tested, shall be present at or in each escape shaft or slope to allow all persons, including disabled persons, to escape quickly to the surface in the event of an emergency. 30 U.S.C. § 877(f)(1). In accordance with this section, the Bureau of Mines developed standards for escapeways and proposed rules a ddressing escapeways. 37 Fed. Re g. 26,422, 26,423– 24 (Dec. 12, 1972). The Bureau not ed that “[b]ecause escapeways should permit rapid exit from a mine in the e vent of an emerg ency, . . . the speed with which exit can be achieved will be increased if escapeways are located to follow the most direct route of travel to the nearest mine opening.” Id. at 26,424. The Bureau thus proposed rule 75.1704-2(a), the predecessorto rule 75.380(d)(5), as “al l travelable passageways designated as escap eways . . . shall be located to follow the most direct route of travel to the nearest mine opening.” Id. But the rule as enacted included the additional clause at issue here: “all travelable passageways de signated as escapeways . . . shall be located to follow . . . the safest di rect practical route to the nearest mine opening suitable for the safe evacuation of miners .” 38 Fed. Reg. 29,997, 30,000 (Oct. 31, 1973) ( emphasis added). The Bureau not ed that “[t]his change was made to emphasize that not only the most direct rout e but also the safest route must be considered i n establishing escapeways.” Id. at 29,998.24 In 1988, MSHA proposed moving th e rule to its current location and recommended changes to the rule . 53 Fed. Reg. 2382, 2407–09 (Ja n. 27, 1988). The proposed rules included require ments for the marking, height, a nd width of
escapeways. Id. at 2408. Regarding § 75.1704-2(a), MSHA stated that “[e]scapew ays would be required to follow the most safe and direct practical route to the surface. Impractical routes would theref ore not be required to be design ated, even though they may be the shortest r outes of travel.” Id. As such, it proposed the rule that the escapeways be “[l]ocated to follo w the most direct and safe pra ctical route to the surface.” Id. at 2422. The final rule required escapeways to be “[l]ocated t o follow the most direct, safe and practic al route to the surface.” 57 F ed. Reg. 20,868, 20,926 (May 15, 1992). During a later revision to the es capeways standards in 1996, MS HA noted confusion over “whether MSHA inte nded that the existing rule el iminate the requirement that escapeways be r outed to the ‘nearest mine open ing.’” 61 Fed. Reg. 9764, 9812 (Mar. 11, 1996). MSHA commented that it was not its “intent to change [the] requirement from the prev ious standard. The existing requ irement that the escapeway follow the most directroute to the surface would, in fact, require the route to go to the nearest mine opening.” Id. “[T]o eliminate any c onfusion,” it adopted language similar to th e previous rule. Id. MSHA acknowledged that “the nearest mine opening may not always be the saf est route to the surface” and different “factors affect whether or not the safes t, most direct, practical route has been selected,” such as “roof conditions, travel height , fan location, physical dime nsions of the mine25 opening, and similar considerations.” Id. It then gave a variety of examples of situations in which the “nearest mine opening” may not be “suit able for safe evacuation of miners,” such as roof falls, coal seam thickness, or old, deteriorated mine shafts. Id. at 9812–13. In response to a s uggestion that MSHA require escapeway plans to be approved “t o assure the most direct route to the surface,” MSHA responded that “inspectors a ssess whether escapeways follo w the most direct, safe and practical route to the s urface during each regular ins pection.” Id. at 9813. MSHA further noted that “[t]he e scapeway should be appropriatel y located and designed to be free of obstructi ons and hazards to assure safe passage from the hazardous underground environment.” Id. at 9810. The rule was thus changed to its current form, mandating that esc apeways be “[l]ocated to follow the most direct, safe and practical route to the neares t mine opening suitable for th e safe evacuation of miners.” Id. at 9843; 30 C.F.R. § 75.380(d)(5). b. The parties’ contentions regarding the regulatory history As noted above, in 1992, when MSHA rephrased the standard, it r eplaced “nearest mine opening suitable fo r the safe evacuation of miner s” with “surface.” 57 Fed. Reg. at 20,926. When it revi sed the standard again in 1996 , it replaced “surface” with “nearest mine opening suitabl e for the safe evacuation of miners.” 61 Fed. Reg. at 9843. The Secretary argues that “MSHA’s consistent treatmentof those words as a unit shows that the phrase ‘suita ble for the safe evacuation of miners’ modifies the term ‘mine opening.’” Appellee’s Br. at 31. Further support forthis argument, according to the Secretary, is f ound in the preamble to the 199 6 rule which states26 “there can be other instances wh ere the ‘nearest mine opening’ may not be suitable for safe evacuation of miners. ” 61 Fed. Reg. at 9813. Even if “ evacuation” were considered complete when a minerleaves the mine, the Secretary contends the regulation requires more; it re quires “safe evacuation.” If min ers were “stranded on a ledge, forced to descend a canyon and hike for miles through th e woods, or forced to scramble thousands of feet up a canyon wall,” they have not yet completed a “‘safe’ evacuation.” Appellee’s Br. at 35. Thus, the Secretary argues, Canyon Fuel’s interpretation, which ignores s urface conditions, “improperly r eads out of the standard the requirement tha t evacuations must be safe.” Id. Canyon Fuel reads the regulatory history differently. It notes that the preamble and examples related to suitabi lity provided in t he regulation each deal exclusively with conditions inside the mine. See 61 Fed. Reg. at 9810, 9 812–13. For example, factors identified as relevant include “roof conditions, travel height, fan location, physical dimensions of the mine opening, and similar considerat ions.” 61 Fed. Reg. at 9812. And the regulatory histo ry further provides that “ther e can be other instances where the ‘nearest mine opening’ may not be suitable for safe e vacuation of miners,” such as “an old mine shaft” that is “not . . . safe for travel because of badly deteriorated conditions, such as a deteriorated shaft lining ordeteriorated timbers.”
Id. at 9813. Because all of these exa mples address conditions exis ting in the mine, Canyon Fuel argues that only un derground conditions are properl y considered. We are not convinced the Secretar y’s “current interpretation ru ns counter to the intent at the time of th e regulation’s promulgation.” Gonzales , 546 U.S. at 25827 (internal quotation marks omitte d). Although it is true that mu ch of the regulatory history refers to cond itions inside the mine , those references are not exclusive. Nothing in the regulatory histor y prevents MSHA from considerin g the conditions facing the miners upon exit from the mine. And the Secretary’s consideration of all conditions of the escapeways, bot h inside and outside the mine, is consistent with selecting the most ac ceptable escapeway—the one that best prote cts the health and safety of the miners. Thus, the Secretary’s interpretation is c onsistent with the intent of the regulation.

c. Consistency with the statute Even if the Secretary’s interpre tation of the regulation is oth erwise reasonable, we will not defer to it if that i nterpretation is in “conflict with the objective of its organic statute,” Time Warner , 381 F.3d at 1050. “To tes t whether an agency’s regulation conflicts with its gove rning statute, we employ the two-step analysis mandated by Chevron . At the first step, w e utilize ‘traditional tools of statutory construction’ to ascertain whet her ‘Congress had an intention o n the precise question at issue.’” Contreras-Bocanegra v. Holder , 678 F.3d 811, 816 ( 10th Cir. 2012) (quoting Chevron, U.S.A., Inc. v. Nat. Res. Def. Council, Inc. , 467 U.S. 837, 843 n.9 (1984)). “[T]he resolution of t his threshold inquiry will be atleast influenced, if not determined, by how broadly we fra me the ‘precise question.’” New Mexico v. Dep’t of Interior , 854 F.3d 1207, 1222 (10t h Cir. 2017) (quoting Bank of Am., N.A. v.
FDIC , 244 F.3d 1309, 1316 (11th Cir. 2001)). “If Congress’ intent i s clear, ‘that is the end of the matter.’” Contreras-Bocanegra , 678 F.3d at 816 (quoting Chevron ,28 467 U.S. at 842). Only if “the st atute is silent or ambiguous w ith respect to the specific issue,” do we proceed to the second Chevron step and determine whether the agency’s interpretation is “base d on a permissible construction of the statute.”
Chevron , 467 U.S. at 843. The Mine Act provision relevant here states: “Escape facilities approved by the Secretary or his authorized repr esentative, properly maintained and frequently tested, shall be present at or in each esc ape shaft or slope to allow a ll persons, including disabled persons, to escape quickly to th e surface in the event of an em ergency.” 30 U.S.C. § 877(f)(1). The “precise question at issue” is what determines whether an escapeway allows miners “to escape quicklyto the surface,” particularly whether it is appropriate to consider surface conditions at th e exit. At step one, we conclu de that Congress did not speak directly to this question; n othing in the statute speaks to whether conditions faced by the miners on the surface may be considered. Under step two of the Chevron analysis, we turn to the Secretary’s interpretation of the regulation, which states that “escap[ing] quickly to the surface” is accomplished through an escapeway that “follo w[s] the most direct, safe and practical route to the nearest mine opening suitable fo r the safe evacuation of miners .” 30 C.F.R. § 75.380(d)(5). Recall that the S ecretary reads the regulation as requiring the consideration of two factors in d etermining which escapeway is the most acceptable. First, the Secretary must assess whether the route is the “mostdirect, safe and practical route to the nearest mine openi ng.” Second, the Secretary must determine whether the mine opening itself is “suitable for the safe evacuation of min ers.” And in assessing the29 suitability of the mine opening, the Secretary deems it appropr iate to consider conditions both at the surface and underground. We hold that the Secretary’s interpretation of the regulation i s a permissible construction of the statute. It furthers the Mine Act’s goal of protecting the health and safety of miners by considering a ll of the circumstances both a bove and below ground in determining whether an escapewa y is the most acceptable. Thus, the regulation as interpreted by the Secretary doe s not conflict with the statute

. * * * Because the Secretary’s interpre tation of the regulation is rea sonable, we defer to that interpretation. The regulation thus requires the selectionof the most acceptable escapeway by consider ing: 1) whether the ro ute is “[l]ocated to follow the most direct, safe and practical route to the n earest mine opening”; and 2) whether that “mine opening” is “suitable for the safe evacuation of miners,” in light of co nditions inside and outside the mine. 30 C.F.R. § 75.380(d)(5). 9 We now consider whether the ALJ properly concluded that Canyon Fuel violated the regulation by designati ng the 4 East Fan Portal as the alternate escapew ay at its Sufco Mine.

9 Canyon Fuel argues that the his tory of non-citation for the 4 East Fan Portal escapeway shows that the currentinterpretation is inconsistentwith prior interpretations and thus undeserv ing of deference. However, the actions of the MSHA District Office do not repre sent the Secretary’s interpret ation of the regulation. See United States v. Mead Corp. , 533 U.S. 218, 233–34 (2001) (thousands of decisions made annually by an a gency’s “scattered” district offices do not have the force of law); Serono Labs., Inc. v. Shalala , 158 F.3d 1313, 1321 (D.C. Cir. 1998) (“But Chevron deference is owed to the decisi onmaker authorized to speak on behalf of the agency, not to each indi vidual agency employee.”). Thus, the lack of citation for over twenty years does not est ablish inconsistency with pri or interpretations.30 B. Evidence of § 75.380(d)(5) Violation 1. Substantial Evidence Standard The ALJ’s factual findings regar ding the occurrence of a § 75.3 80(d)(5) violation are conclusive if th ey are supported by substantial e vidence. See 30 U.S.C. § 816(a)(1) (“The findings of th e Commission with respect to qu estions of fact, if supported by substantial eviden ce on the record considered as a whole, shall be conclusive.”). Substantial evidence is such ev idence that a reasonable mind mi ght accept as adequate to support the conclu sion reached by the decisionmaker. Substantial evidence requires more than a scintilla, but less than a preponderance. The possibility o f drawing two inconsistent conc lusions from the evidence does not preve nt an administrative agency’s f indings from being supported by substan tial evidence. Thus, we may not displace the agency’s choice between two fairly conflicting views, even though the court would justifiably have mad e a different choice had the matter been before it de novo. Plateau Mining Corp. , 519 F.3d at 1194 (internal qu otation marks omitted). “We neither reweigh the evidence nor substitute our judgment for that of th e agency.” Andalex Res., Inc. v. Mine Safety & Health Admin. , 792 F.3d 1252, 1257 (1 0th Cir. 2015) (internal quotation marks omitted). “[O]ur review is very deferential to the agency.” Id. (internal quotation marks omitted). To establish a violation of § 75. 380(d)(5), however, “[i]t is i nsufficient for the Secretary to merely cite the des ignated route as being out of c ompliance with the regulation.” S. Ohio Coal , 14 FMSHRC at 1785. Rather, “ it is the Secretary’s burden to prove that, as compared to th e designated route, there is at least one other escapeway route that [he] has de termined more closely complies with the standard’s31 requirement.” Id. The Secretary must identify “a specific escapew ay alternative that more fully complies w ith [the standard’s] criteria than does th e cited route.” Id. Thus the question before us is wheth er substantial evidence shows th at the West Lease Portal escapeway more closely complies with § 75.380(d)(5) than does the 4 East Fan Portal escapeway. Thi s entails a comprehe nsive comparison of both factors identified in the regulation: which route is “[l]ocated to f ollow the most direct, safe and practical route to the nearest mine opening” and whether the mi ne openings are “suitable for the safe evacuati on of miners.” Only after consid eration of the relative advantages and disadvantages of ea ch escapeway as to both regul atory factors can the Secretary make a rational choi ce between them. That is, the Sec retary must evaluate the relative acceptability of the proposed alternate escapeways by considering both the practicality of eac h route and the suit ability of each mine opening. Upon review of the record as a w hole, we conclude the Secretary failed to engage in that comprehensive comparison and, therefore, substan tial evidence does not support a finding that the Wes t Lease Portal is the more ac ceptable alternate
escapeway. 2. Application According to the ALJ, “the Secre tary established that Canyon Fu el’s route [the 4 East Fan Portal rout e] was deficient.” Canyon Fuel I , 38 FMSHRC at 2217. The ALJ further explained: The escapeway to the 4 East Fan Portal did not account for the fact that miners would be stranded there on ce they exited the mine. This fact would create a hazard to escaping miners particularly in cold o r snowy32 weather and more especially if a ny miners are seriously injured . The Secretary presented a specific e scapeway alternative he believe s provides for a safer, direct, pra ctical route for escaping mine rs. The Secretary took into considerati on a number of factors, includin g those discussed above. MSHA’s proposed e scapeway is drivable for mostof its length and is mostly in a sep arate intake air course. This air course would not be affected by a fire i n the working section or the b elt. Although the alternative escapewa y favored by the Secretary is longer than Canyon Fuel’s, it is similarin length to the primary escapeway. [Ms.] Yeager traveled the Secret ary’s proposed route and testif ied that the overcasts are not difficult to negotiate, noting that there were wellbuilt stairs. The Secretary acknow ledges that if SCSRs are need ed, miners will need to change them out more frequently using the W est Lease Portal escape route. Fin ally, any escaping miners[,] who must remain at the 4 East Fan Portal for a period of time before the y can be rescued, could be ove rcome by smoke and toxic fumes. The Secret ary maintains that in considering al l the factors set forth in the safety standard, his designated alternat ive escapeway is the safest di rect practical route.
Id. at 2217–18 (cit ation omitted). It is unclear from the ALJ’s opi nion whether he found the 4 Eas t Fan Portal mine opening “[un]suitable for th e safe evacuation of miners” o r whether he found the opening suitable but also f ound the West Lease Portal escap eway more acceptable. 10 We need not resolve this issue because under either analysis, the decision is not supported by substantial evidence.

10 The Secretary reads the ALJ’s decision as finding the 4 East F an Portal unsuitable both in his brief bef ore the Commission and in his b rief before us. And that is also the view taken by the affirming commissioners. Sec’y of Labor, Mine Safety & Health Admin. v. Canyon Fuel Co. , 39 FMSHRC 1578, 1588 n.11 (2017) (“ Canyon Fuel II”) (affirming commissioners) (“ The termination point of this escapeway failed to provide for ‘ safe evacuation of miners,’ as the standard requires, and thus was not ‘suitable.’”) . But the reversing commissioners did not view the ALJ's opinion in that manner. The y rejected the “assert[ion] th at the Secretary’s representative did make a determ ination that the [4] East Fan P ortal route was per se unsuitable because it would not s afely evacuate the miners” and instead noted that33 Even accepting that a mine opening must be at least minimally “ suitable for the safe evacuation of miners” before it can be considered as part of an acceptable alternate escapeway, the record evidence must allow for such a conclusion . For example, if an escapeway plunges to the canyonfloor or leads to a shelf so sm all that it cannot accommodate all of the escaping miners, the Secretary may not b e required to look beyond the mine opening’s unsu itability to prove a violation of § 75.380(d)(5). 11 But such situations are rare and in t he vast majorityof cases, the Secretary must make a comprehensive comparison of bot h the practicality of the routes and the suitability of the mine openings to determine that one escapeway is more acceptabl e than another. As previously discussed, the text and history of the escapeways st atute and regulations are focused on underground conditi ons, including with respect to th e suitability of mine openings. See supra Sections II.A.1.b, II.A.2 .a. Although we have concluded this f ocus does not preclude the Secretary fro m also considering above-gro und conditions, not even the Secretary suggests that he can consider such above-ground c onditions to the exclusion of underground conditions. Instead, the Secretary has argued th at “[w]hether a mine opening is ‘suitable for the saf e evacuation of miners’” is “ananalysis that must take into account conditions both underg round and at the surface .” Appellee’s Br. at 26 (emphasis added). And the Secretary acts arbitrarily if he “entirely fail [s] to consider an important

this was “not a case of se lf-evident unsuitability.” Id. at 1593 & n.12 (reversing commissioners).

11 Even where a cited alternate es capeway does not lead to a suit able mine opening, it is possible that the p roposed alternate escapeway i s also deficient either due to a similarly unsuitable mi ne opening or due to a complete ly impractical route.34 aspect of the problem.” Ariz. Pub. Serv. Co. v. U.S. E.P.A. , 562 F.3d 1116, 1123 (10th Cir. 2009) (quoting Motor Vehicle Mfrs. Ass’n of the U.S. v. State Farm Mut. Auto. Ins.
Co. , 463 U.S. 29, 43 (1983)). That is what happened here. Considering only above-ground c onditions can also lead to absur d results. Suppose that, instead of the hos pital being located fifty miles from the West Lease Portal, it is located f ifty feet away. This would make the surf ace conditions at the West Lease Portal quite beneficia l, especially compared to the 4 East Fan Portal. But also suppose the underground escap eway leading to the West Leas e Portal is one hundred miles long instead of s ix miles long and includes numer ous overcasts or heightened risk of contaminated air. The Secretary’s piecemeal consideration of only above-ground conditions at the mi ne openings leads to the concl usion that the West Lease Portal is “suitable” while t he 4 East Fan Portal remains “unsuitable,” despite the significant potential haza rds posed by a much longer underg round trek. The Secretary must perform a holistic analysis and consider both th e underground and the surface conditions at the We st Lease Portal and its route and compare those conditions with the corresponding s urface and underground condi tions of the 4 East Fan Portal and its rou te to properly determine which escapeway is most acceptable because it is locat ed to follow “the mostdirect, safe and practic al route to the nearest mine opening suitable for the sa fe evacuation of miners,” 30 C. F.R. § 75.380(d)(5) (emphasis added). Here, there is not substantia l evidence to support a finding th at the 4 East Fan Portal is per se “[un]suitable fo r the safe evacuation of miner s.” As the Secretary35 admits, suitability of the mine opening “depends on conditions both underground and at the surface.” Appellee’s Br. at 24 (emphasis added). To be s ure, the surface conditions at the 4 East Fan Portal are not ideal—potentially leav ing injured miners stranded inside the fan house f or some indeterminate period unt il the weather permits helicopter evacuation or forcing them to make challenging ascen ts or descents, possibly through a foot or more o f snow, to seek medical assist ance that is still miles away. This evidence may show the 4 East Fan Portal is less suitable than the West Lease Portal; however, it does no t show that the 4 East Fan Por tal is unsuitable

. Miners may be stranded on the sh elf awaiting rescue from a heli copter, Canyon Fuel
I , 38 FMSHRC at 2217, but there a re multiple buildings in which they could wait pending rescue. The fan house is warm all year round when the f an is running, includes first aid and communica tion equipment, and would fit a ll the escaping miners. Id. at 2211. And when conditions are favorable, a helicopter could transport the miners to medical care. As an alternative, the miners couldtraverse the cattle trail to the gravel road or the path t o the top of the canyon to the Forest Service road for medical transportation. Miners ca n evacuate safely from the 4 E ast Fan Portal and thus it is at least minimally su itable. Therefore, the Secretary was required to make a comprehensive comparison between t he two proposed escapeways be fore selecting the most acceptable. And because the 4 East Fan Portal is at least minimally suitabl e, the ALJ’s finding that the West Lease Portal escapeway is th e most accept able is not supported by substantial evidence. The recor d lacks any meaningful compar ison by the36 Secretary of the two alternate es capeways: the 4 East Fan Porta l escapeway and the West Lease Portal escapeway. Inst ead, the Secretary presented e vidence at the administrative hearing focused on the difficulty of evacuating miners from the ledge at the 4 East Fan Port al, almost to the exclusion of evidence a bout the comparative underground conditions of the two proposed alternate escapeways

. See, e.g. , Joint App. at 8 (opening statement of Alicia Truman: “[A]lthough thatroute may be the shortest, most direct way to a mine exit, it did not lead to a mine opening suitable for the safe evacuation of miners.”); id. at 16, 20 (testimony o f Mr. Riley: “Q: And why do you believe that the 4 East f an portal is not mine opening [ sic ] suitable for the safe evacuation of miners? A: Because once miners would come out the re, there is no reasonable means to get the miner s, including disabled miners, off of the canyon edge,” and “[T]his 4 Ea st ledge is not suita ble for the safe ev acuation of miners.”);
id. at 45 (testimony of J ames Preece: “Q: Okay . After personally v iewing the portal area to the 4 East fan, did you form any opinions as to whetherthat mine exit was suitable for the safe evacuation of miners? A: I did. Q: And wh at conclusion did you draw? A: It would not be suitab le.”). Indeed, at various times, the Secretary compared its proposed alte rnate escapew ay with the primary escapeway, rather than with the 4 East Fan Portal route. See, e.g. , Id. at 39 (testimony of Mr. Riley: “Q: . . . How does that distance compare to if miners now had to carry an injured miner out of the mine’s primary es capeway? A: It would be the same distance. ”); Appellee’s Br. at 52 (“The West Lease route is longe r than the 4 East Fan route, but it is no longer than37 the primary escapeway route.”). B ut in so doing the Secretary h as improperly omitted half of the required analysis. The failure to make a comprehensi ve comparison between the two proposed escapeways can also result in mis leading information. For examp le, the distance to potential medical transportation between the two routes is much closer than the Secretary argues: for the 4 East Fan Portal route, miners must travel between 6 and 7 miles (2.34 miles underground a nd between 4 and 5 miles on the cattle trail) and for the West Lease Portal route, min ers must travel 5.88 miles (all underground). 12 Contrary to the Secretary’s asse rtions, the proper comparison i s not between immediate evacuation at the West Lease Portal and a four to fiv e mile trek at the 4 East Fan Portal. Instead, selec tion of the most acceptable escapeway requires careful assessment of the entire escape odyssey—from the moment of the hypothetical mine emergency to the provision of m edical services to the evacuated miners. To be sure, substantial evidence sup ports a finding that the surface conditions at the 4 East Fan Portal are less suitable than the corresponding surface conditi ons at the West Lease Portal. But that is only part of the analysis: the regulation r equires consideration of those limitations in conjunction with whatever advantages or di sadvantages the 4 East Fan Portal route may offer within the mine, and then a com parison of those pros and cons with the same informati on about the Secretary’s prefer red alternate route—

12 The only evidence comparing this aspect of the two routes is t hat the four to five mile trek after exiting the 4 East Fan Portal would take two hours without snow or injury while the West Lease Portal escapeway would take three hours without an emergency or injury. T his is, of course, assuming that a helico pter would be unable to rescue the miners from the 4 East Fan Portal.38 the West Lease Portal. The evide nce necessary to make this comp arison simply was not presented to the ALJ. It is uncontroverted that the 4 Ea st Fan Portal is the “most di rect” route out of the mine. See, e.g. , Joint App. at 8 (opening state ment of MSHA: “[A]lthough [the 4 East Fan Portal route] may be th e shortest, most direct way to a mine exit . . .”); id. at 31 (testimony of Mr. Riley: “It is the shortest route out. . . . I would say it’s the most direct route out.”); id. at 58 (testimony of Sydel Yaeger : Q: . . . [T]he quickest—the shortest route out from 5 West i s to come out the 4 East portal s, isn’t that right? A: Yes. Q: And it’s the most direct; isn’t that right? A: Well, ye ah, shortest, direct.”). And the objective indicators of t he “difficulty” of traversing the paths suggest that the 4 East Fan Portal route, at least while underground , may also be the most practical and safe. It “is shorte r, requires fewer SCSRs to be available, and requires fewer overcast crossings.” Appe llee’s Br. at 53. Furthermore, i t has fewer turns than the proposed West Lease Portal r oute, which has “some turns.” Id. The Secretary made little effort to present evidence comparing the underground conditions of the tw o escapeway routes. Instead, th e Secretary presented evidence of the proposed alternat e escapeway in isolation and, to some extent, in comparison with the primary rout e or with the above-ground cond itions at the 4 East Fan Portal. For example, while t here is evidence that the propo sed West Lease Portal escapeway could be traversed i n three hours under ideal conditi ons, Canyon Fuel I , 38 FMSHRC at 2212, there is no ev idence of how long it would ta ke to traverse the 4 East Fan Portal escapeway in s imilar conditions, or how long either route would take39 in an emergency. Because the 4 E ast Fan Portal route is over 3. 5 miles shorter than the West Lease Portal route, and contains fewer turns, overcast s, and SCSR changeouts, that information might wel l have impacted the ALJ’s analy sis. The record did not permit the AL J to assess the advantages of t raveling the 4 East Fan Portal route as opposed t o the West Lease Portal route , if any. And because of that gap, the ALJ never weighe d the benefits of exiting the mine more quickly along the 4 East Fan Portal rout e, with a potentially indetermi nate wait for transportation to medical facil ities at the mine opening, again st the benefits of receiving medical care more qui ckly, but first enduring a longe r and possibly more difficult journey to exit the mi ne. Depending on the circumstan ces, attaining the surface quickly may be of paramou nt importance, whereas in othe r instances the opposite may be true. Compare for example a situation where the air within the mine has become contaminated by meth ane gas, with a situation where an isolated collapse has blocked the main escapeway and caused life-threatening inju ries to one or more miners. In the first case, the f astest route to the surface may be preferable, even if the wait for medical care at the min e opening is longer. In contras t, where significant medical attention is needed, as in the second example, the abil ity to transport the miners quickly to a medical facil ity may be most important. In sum, mining disasters come in different forms and it is no small burden to predict wh ether the next emergency would be best served by the fastest route to the surf ace or the fastest route to medical services. Had the A LJ been presented with and consid ered all the relevant facts, it would not be our place to second guess his decision w ith respect to that40 difficult choice. But the record did not allow for such a compr ehensive analysis. As a result, the ALJ’s finding that the West Lease Portal escapeway is more acceptable than the 4 East Fan Portal esc apeway is not supported by substa ntial evidence. 13

III. CONCLUSION We AFFIRM the Secretary’s interp retation of the regulation. Bec ause substantial evidence does not supp ort the ALJ’s finding that Ca nyon Fuel violated the regulation, we REVERSE the deci sion of the ALJ and VACATE the c itation.

13 Nothing in our decision is inten ded to suggest that the 4 East Fan Portal escapeway is more accep table than the West Lease Portal escapew ay. Nor do we imply that, with the proper evid entiary record, the Secretary c ould not establish a violation of the regul ation at the Sufco Mine. The potential fo r miners, including those seriously injured in the pr ocess of escaping an undergrou nd disaster, to be trapped on a ledge in cold or s nowy weather is legitimate cause for concern. But any decision that another escapeway i s more acceptable must be base d on an evidentiary record that permits a comparison of the relative practicality o f the proposed route, as well as the suitability o f the mine opening.