The Montana State Highway Commission was created in 1913 by the state Legislative Assembly. The original Commission was composed of three members. In 1917 new legislation altered the organization of the Commission by authorizing the appointment of twelve members according to geographic highway districts. Membership was changed again in 1921 to three members appointed by the Governor and in 1941 to five members, also appointed by the Governor. In 1971 the Commission was renamed the Montana Department of Highways, created by Chapter 7 of the Executive Reorganization Act of 1971 and implemented by executive order of the Governor on December 16, 1971. The Department of Highways took over all but the advisory functions of the State Highway Commission.

By 1972, the Department consisted of seven divisions: the Legal Division, Personnel Division, Centralized Services Division, Engineering Division, Motor Pool Division, Gross Vehicle Weight Division, and the Maintenance Division. Each division is headed by an administrator. The Centralized Services Division, Engineering Division, Motor Pool Division, Gross Vehicle Weight Division, and the Maintenance Division are furthered sub-divided into bureaus, headed by Chiefs. In 1991, the Department of Highways became the Department of Transportation. This was primarily a name change. However, there were some structural and administrative changes.

The Highway Department, the Department of Highways, and Department of Transportation maintained regional offices in the five commissioner districts: Billings, Butte, Glendive, Great Falls, and Missoula. The District Engineer (later called the District Administrator) was the chief administrative officer in each district office. District office files document the activities of the district administrators, engineers, maintenance crew, and other district office employees. The district offices addressed administrative, functional, and project related issues of their particular area, including: highway needs, current construction projects, HR/training for employees, road design, federal and state aid and grants, reports to the Department of Highways/ Department of Transportation in Helena regarding general maintenance, construction, and area concerns, etc. District administrators held meetings every 6 weeks. Other employees in the district and area offices also attended duty-specific meetings with outside district staff members; including maintenance crew meetings, engineer meetings etc., in order to maintain consistent communication among the districts and with other state agencies regarding programs, projects, and district goals. The files in the district office were kept by the District Engineer/Administrator.