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PacifiCorp v. Environmental Protection Agency

Consolidated with:

Docket No. Op. Below Argument Opinion Vote Author Term
23-1068 10th Cir. Mar 25, 2025 Jun 18, 2025 8-0 Thomas OT 2024

Holding: Under the Clean Air Act, EPA’s disapprovals of the Oklahoma and Utah state implementation plans are locally or regionally applicable actions reviewable in a regional court of appeals.

Judgment: Reversed and remanded, 8-0, in an opinion by Justice Thomas on June 18, 2025. Justice Alito took no part in the consideration or decision of the case.

SCOTUSblog Coverage

DateProceedings and Orders (key to color coding)
03/28/2024Petition for a writ of certiorari filed. (Response due May 1, 2024)
04/23/2024Motion to extend the time to file a response from May 1, 2024 to May 21, 2024, submitted to The Clerk.
04/24/2024Motion to extend the time to file a response is granted and the time is extended to and including May 21, 2024.
05/21/2024Brief for the Federal Respondents filed. VIDED.
05/23/2024Waiver of the 14-day waiting period for the distribution of the petition pursuant to Rule 15.5 filed by petitioner.
05/28/2024DISTRIBUTED for Conference of 6/13/2024.
05/29/2024Rescheduled.
05/30/2024Reply of petitioners PacifiCorp, et al. filed.
09/11/2024DISTRIBUTED for Conference of 9/30/2024.
10/07/2024DISTRIBUTED for Conference of 10/11/2024.
10/15/2024DISTRIBUTED for Conference of 10/18/2024.
10/21/2024Petition GRANTED. The petition for a writ of certiorari in No. 23-1067 is granted. The cases are consolidated, and a total of one hour is allotted for oral argument. Justice Alito took no part in the consideration or decision of these petitions. VIDED.
10/21/2024Because the Court has consolidated these cases for briefing and oral argument, future filings and activity in the cases will now be reflected on the docket of No. 23-1067. Subsequent filings in these cases must therefore be submitted through the electronic filing system in No. 23-1067. Each document submitted in connection with one or more of these cases must include on its cover the case number and caption for each case in which the filing is intended to be submitted. Where a filing is submitted in fewer than all of the cases, the docket entry will reflect the case number(s) in which the filing is submitted; a document filed in all of the consolidated cases will be noted as “VIDED.”
02/10/2025SET FOR ARGUMENT on Tuesday, March 25, 2025. VIDED.
02/12/2025Record requested from the United States Court of Appeals for the Tenth Circuit.
02/12/2025Record received electronically from the United States Court of Appeals for the Tenth Circuit and available with the Clerk.
02/18/2025Reply of petitioners PacifiCorp, et al. filed. VIDED. (Distributed)
02/19/2025CIRCULATED
03/25/2025Argued. For petitioners in 23-1067: Mithun Mansinghani, Oklahoma City, Okla. For petitioners in 23-1068: Misha Tseytlin, Chicago, Ill. For respondents: Malcolm L. Stewart, Deputy Solicitor General, Department of Justice, Washington, D. C. VIDED.
06/18/2025Judgment REVERSED and case REMANDED. Thomas, J., delivered the opinion of the Court, in which Sotomayor, Kagan, Kavanaugh, Barrett, and Jackson, JJ., joined. Gorsuch, J., filed an opinion concurring in the judgment, in which Roberts, C. J., joined. Alito, J., took no part in the consideration or decision of the case. VIDED.
07/21/2025Judgment Issued.