agency’s decision not to prepare the original EIS, the “legal standard for determining when a supplemental EIS is required is ‘essentially the same as the standard for determining the need for an original EIS.’ ” Fritiofson, 772 F.2d at 1239 n. 8 (citation omitted). Oregon Natural has plainly emasculated our precedent applying the reasonableness standard with respect to the review of an agency’s decision to forego a supplemental EIS. See Oregon Natural, 109 S.Ct. at 1861 n. 23 (citing with disapproval our decision in Sierra Club v. Froelhlke, 816 F.2d 205, 210 (5th Cir.1987)). We believe that it has similarly undercut our precedent applying the reasonableness standard with respect to an agency’s decision to forego the original EIS. See Lockhart v. Kenops, 927 F.2d 1028, 1032 (8th Cir.) (<HOLDING>), cert. denied, — U.S. -, 112 S.Ct. 186, 116
holding that a threejudge panel may depart from circuit precedent that has not been expressly overruled when an intervening en banc or supreme court decision has undercut the theory or reasoning underlying the prior circuit precedent in such a way that the cases are clearly irreconcilable holding that judicial review of an administrative agencys decision is limited solely to whether given the relevant standard and facts the agencys decision was arbitrary illegal capricious or unreasonable holding that an intervening supreme court case can overturn circuit precedent holding that the intervening decision of oregon natural undercut eight circuit precedent applying the reasonableness standard with respect review of an agencys decision to forego preparation of an original eis holding that an agencys decision not to prepare an eis was unreasonable because record demonstrated that four of the regulatory factors were implicated