Miller Brothers, Inc. was a Chinook, Cleveland, and Lloyd, Montana, sheep and cattle ranch operated by Henry G. Miller, his brother Chris D. Miller, and G.T. "Ted" Westin, son-in-law of Chris Miller. Records (1894-1966) include general correspondence, court papers, legal documents, and financial records documenting the operation of the ranch; and materials on the First National Bank of Chinook, which the Millers helped organize in 1909.

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.