The Montana Council of Defense was established during World War I to coordinate county war efforts. It also investigated cases of alleged disloyal activities. Records (1916-1921) include minutes, correspondence, subject files, testimony and exhibits for hearings and special investigations, membership lists, and correspondence of various county councils of defense.

O'Brien family papers (ca. 1889-1982) collection includes family and business papers created and kept by the John and Ellen O'Brien family of Newlon, MT. Includes biographical material, correspondence, court papers, financial records, legal documents, printed material, clippings, and ephemera. Material related to family, the family run store/stage stop/hotel, and son Ted, who served as sheriff in Richland Co., including material related to the 1929 Fairview Bank robbery.