The Montana Trust and Savings Bank of Helena was organized in 1913 by Thomas A. Marlow. Marlow had previously been president of the Montana National Bank (1891) and an organizer of the National Bank of Montana (1901). Montana Trust and Savings Bank was originally located at the corner of Main and Edwards streets, but moved to the ground floor of the Montana Club building in the early 1920s. Officers of the bank during its eighteen years of operation included Albert L. Smith, vice president; Leon S. Hazard, cashier; Walter Brutsch, secretary; Trevor 0. Hammond, cashier and vice president; Lloyd G. Kiest, assistant cashier; and Frank S. Lange, cashier. Montana Trust and Savings Bank, affiliated with the National Bank of Montana (Helena), had capital, surplus, and undivided profits amounting to $250,000 in 1927.

In addition to offering a general banking business to its clients, the bank handled trusts for corporations and individuals. The firm and its officers also appear to have been involved with war relief activities during World War I, raising funds, selling Victory Bonds, and supporting the Red Cross and Montana Loyalty League. There may also have been some level of affiliation between Montana Trust and Savings and the First National Bank of Lewistown. On May 1, 1931, three Helena banks (Montana Trust and Savings, National Bank of Montana, and American National Bank) were consolidated to form First National Bank and Trust Company.