dissenting, in which GOLDEN, Justice, joins.
[T21] I respectfully dissent. W.RA.P. 12.01 and 12.03 clearly require the review of administrative agency decisions to be "instituted by filing a petition for review." W.R.A.P. 12.04(a) requires the petition to be filed within 30 days after service of the final agency decision. If that requirement is not met, it can be overcome under W.R.AP. 12.04(b) by a showing of excusable neglect, coupled with a request for a filing extension not to exceed an additional 30 days. None of that happened in this case.
[122] The timely filing of a petition for review of administrative action is mandatory and jurisdictional. Chevron U.S.A. v. Dep't of Revenue, 2007 WY 62, ¶ 7, 155 P.3d 1041, 1043 (Wyo.2007); Nyberg v. State Military Dep't, 2003 WY 43, ¶ 30, 65 P.3d 1241, 1249 (Wyo.2003); Sheridan Ret. Partners v. City of Sheridan, 950 P.2d 554, 557 (Wyo.1997); Dep't of Revenue & Taxation v. Irvine, 589 P.2d 1295, 1301 (Wyo.1979). Admittedly, we have softened the blow of that pronouncement by declaring that the reviewing court does acquire jurisdiction "so long as some document evidencing an intention to seek judicial review is timely filed." McElreath v. State ex rel. Wyo. Workers' Comp. Div., 901 P.2d 1103, 1106 (Wyo.1995); In re Claim of Taffner, 821 P.2d 103, 107 (Wyo.1991). All that means, however, is that, where an insufficient petition for review has been filed, the reviewing court has jurisdiction to apply the rules of appellate procedure in deciding what to do with it.1 That is where I would break from the majority's analysis. I would not hold that the discretionary language of the second sentence of W.R.A.P. 1.03 goes so far as to negate the specific requirement of W.R.A.P. 12.04(b) that excusable neglect be shown in order to enlarge the time for filing a petition for review. Here, where there was no attempt to make such showing, the proper course was that taken by the district court; that is, to dismiss the notice of appeal. It is clear from the Order of Dismissal that the district court recognized the discretionary nature of the second sentence of W.R.A.P. 1.03, but that it also recognized that "[these proceedings are governed by Rule 12 of the Rules of Appellate Procedure." Its effective conclusion was that Rule 12 does not provide an alternative to the excusable neglect process of W.R.A.P. 12.04(b) in the nature of an untimely amendment of a faulty filing. I agree with that conclusion.
[123] Finally, I would say that McElreath is poor precedent because it relied upon Taffner, in which this Court mistakenly applied present W.R.A.P. 9.04-the harmless error rule-in ruling upon an appellate error. *128The harmless error rule, as well as the plain error rule found in W.R.A.P. 9.05, are applied as part of this Court's review of what took place below, not as part of this Court's review of appellate error. Beyond that, McElreath, 901 P.2d at 1106, and Taffner, 821 P.2d at 107, are inconsistent in their treatment of prejudice in the review of appellate error.
. I do not believe that W.R.C.P. 15 governing the amendment of pleadings should play any role in this process.