This collection is a subgroup (Division) of the Montana Department of Environmental Quality records, RS 494. The Environmental Sciences Division formerly operated within the Department of Health and Environmental Sciences until it split from DHES in 1995 to form the Department of Environmental Quality. Please see the primary finding aid for more Montana Department of Environmental Quality records.

This collection consists of two subgroups: General files from the Environmental Science Division and Tom Ellerhoff’s files from the division.

The general Environmental Science Division files consist of eight series: Correspondence, Court Papers, Financial Records, Hearings, Laboratory Records, Organizational Records, Reports, and Subject Files, and Miscellany. Subject matter includes soil and water testing for arsenic, bacillus coli, and cyanide, industrial use of water, community sanitation, water maintenance schools, legislation, and the Dean William Cobleigh Memorial Scholarship. More specifically, the Laboratory Records include water quality basic data reports for the Yellowstone River. Also of interest are the Subject Files (1918-1969), which contain information on the American Smelting and Refining Company plant at East Helena; Austin's Packing Company in Glasgow; the Big Sky Development Corporation's wood fiber plant/pulp mill on the Flathead River near Kalispell; Libby Dam; privies, including State Board of Health circular 13 on building a sanitary pit privy; tularaemia, and the Waldorf Paper Products Company pulp mill near Missoula.

Tom Ellerhoff’s files consist of four series: Church Universal and Triumphant (CUT), Lasting Legacy: Montana’s Environmental Health Pioneers (LL), Subject Files, and Press Clippings. CUT and LL primarily consist of reference material, drafts, and correspondence for the writings of Tom Ellerhoff on those subjects. Subject Files include the 1989 Helena Train Derailment, Bonneville Power Administration (BPA), the Internal Organ Newsletter, and Transisco Rail.