Environmental Protection Agency · EPA-R08-OAR-2024-0608
Air Plan Approval; Montana; Regional Haze Plan for the Second Implementation Period
The Federal Register published the matched proposal on September 11, 2025 and the matched final rule on November 28, 2025, 78 days later.
Official publication history
Proposal ·
Air Plan Approval; Montana; Regional Haze Plan for the Second Implementation Period; Prong 4 (Visibility) for the 2015 8-Hour Ozone National Ambient Air Quality Standard
Comment date listed October 14, 2025
Final rule ·
Air Plan Approval; Montana; Regional Haze Plan for the Second Implementation Period
Effective date in register data December 29, 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.
Federal Register data source · Search Regulations.gov · Download this snapshot