This collection is a sub-subgroup (Bureau) of the Montana Department of Environmental Quality records, RS 494. The Air Quality Bureau (formerly named Air Resources Management Bureau) currently operates within the Air, Energy, and Mining Division. Please see the primary finding aid for more Montana Department of Environmental Quality records. These records (1965-2001) include correspondence, case files, hearing transcripts, and subject files.

This collection is composed of correspondence, case files, hearing transcripts, and subject files. The correspondence series is comprised mostly of correspondence between the AQB/ARMB and the Environmental Protection Agency, and correspondence in regards to State Implementation Plans to deal with air pollution in various cities, including Anaconda, Butte, East Helena, Libby, Missoula, and Whitefish. The Case Files series is alphabetized by company, and deals primarily with permitting and compliance. The Hearings series is comprised of transcripts of hearings for air quality cases between 1977 and 2000. Hearings revolve primarily around the adoption of air quality rules. The highlights of the Subject Files series are folders dealing with the EPA’s Clean Air Act of 1990, citations and complaints for emissions violations, and air quality quarterly contract reports by county (not all counties are represented).