Environmental Protection Agency · EPA-R08-OAR-2019-0418
Air Plan Approval; Montana: Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards
The Federal Register published the matched proposal on July 16, 2025 and the matched final rule on November 18, 2025, 125 days later.
Official publication history
Proposal ·
Air Quality State Implementation Plans; Approval and Promulgations: Montana: Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards
Comment date listed August 15, 2025
Final rule ·
Air Plan Approval; Montana: Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards
Effective date in register data December 18, 2025
About this timeline
How the records were matched
America.co links a proposed rule and a later final rule when the Federal Register records share the exact docket identifier and lead agency. This snapshot covers records published from January 1, 2025 to November 10, 2026.
A docket can hold more than one regulatory action. Dates here are dates listed in individual notices. Later corrections, court actions, other dockets and records outside the date window may change what applies. Follow the official documents for the full text and effective dates.
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