The society provides services through six operational programs: Administration, Research Center, Museum, Publications, Historic Preservation, and Education.

[3][4] The bill, "An Act to Incorporate the Historical Society of Montana", was signed into law February 2, 1865 "in order to collect and arrange facts in regard to the early history of this Territory, the discovery of its mines, incidents of the fur trade, etc."

[2] On March 25, 1865, members of the society elected Wilbur Sanders President, Granville Stuart Secretary-Treasurer, and the Honorable Hezekiah L. Hosmer Historian.

[1] The archives collections include manuscripts from the early 1860s to the present, in addition to a large number of oral histories, mostly from the 20th and 21st centuries.

Other displays include Native Americans, settlers and home life, mining, frontier weapons and a white bison mount.

In November 2023, Brian D'Ambrosio was indicted on 10 counts related to theft of objects of cultural heritage from the Montana Historical Society which he offered for sale on eBay or to private collectors.

[12] The prosecution argued that the items D’Ambrosio stole would bring him significant profit, such letters from Nancy Russell, wife of artist C.M.

[13] U.S. Attorney Jesse Laslovich stated at sentencing, “D’Ambrosio’s actions were intentional and calculated—designed to steal Montana’s cultural treasures so he could profit.