In Sierra Club v. Wisconsin Department of Natural Resources, 2005 AP 1106, the Court of Appeals confirmed that failure to serve all certified parties in the administrative agency proceeding is fatal to Circuit Court subject matter jurisdiction in appeals under Chapter 227. One of several challenges to the We Energies expansion of its Oak Creek Power Plant, this case involved Sierra Club’s attempt to appeal the DNR permit issued to authorize certain wetland and waterway impacts associated with the construction under Chapter 30 of the Wisconsin Statutes. In his decision issuing the permit, the Administrative Law Judge (ALJ) certified the parties to that proceeding. Sierra Club failed to serve two of those certified parties with its petition for judicial review of the ALJ’s decision. The Circuit Court dismissed the proceeding for lack of subject matter jurisdiction, rejecting Sierra Club’s argument that the holding of Wisconsin’s Environmental Decade v. PSC, 84 Wis. 2d. 504 (1978), had been altered by amendment of the statute. The Court of Appeals decision confirms the longstanding interpretation of Section 227.53(1)(c) that service of a petition seeking judicial review of an agency decision must be made on all parties who appeared in the agency proceeding within 30 days after the proceeding is initiated or the Court is deprived of subject matter jurisdiction. This opinion is not recommended for publication.