History and Area of Responsibility
On December 6, 1987 the St Mary, MT substation was incorporated and one (1) Journeyman Agent was assigned under the supervision of the Shelby Supervisor. In April of 1988 one additional Agent was assigned to the St. Mary substation bringing it to its present status to two Senior Patrol Agents.

The St. Mary substation now has responsibility for the area that was covered by the Browning substation and includes the Blackfeet Indian Reservation and all of the Shelby station area west of U. S. Highway # 89. The two agents of the St. Mary substation are housed in doublewide mobile homes south of the Port of Entry (POE) at Piegan, MT.

The station was originally established in Browning, MT in 1934 and consisted of two Journeymen Agents and operated until 1946 when it was deactivated. In 1956 a Border Patrol trailer was set up at Kiowa Junction, west of Browning, and used as a residence and office for agents on detail. Agents were detailed to Browning on a rotational basis from within Havre Sector.

The Browning station was reactivated in 1957 with one Supervisor and two Journeymen Agents. In 1960 the office was moved into rental quarters on West Pata Street, Browning, MT and one additional Journeyman Agent was assigned to the station.

In June of 1966 construction was completed on a Border Patrol complex located adjacent to U. S. Highway 2 about one-half mile west of the Browning city limits. The new complex consisted of an office and three individual residences. In 1966 personnel strength was reduced to one Supervisor and one (1) Journeyman Agent position. Border Patrol Agents occupied two of the residences on a continuing basis and the third residence was rented to non-service personnel. The acting Supervisor at the Shelby Station was designated as acting supervisor during several periods of time when no supervisor was assigned to the Browning Station. On June 30, 1973 the supervisory position was replaced by a Journeyman position.

Effective July 1, 1973 Browning was designated a substation under the supervisor at Shelby. Personnel strength remained at two Border Patrol Agents until the official closure of the station on August 4, 1983. The Border Patrol complex at Browning was transferred to GSA for reassignment to other Federal Agencies. The Agents of the Shelby station covered this area until the St. Mary substation was incorporated in 1987.

The St. Mary, MT substation’s area of responsibility is comprised of 7,800 square miles of mountainous terrain and rolling prairie farm and ranch land. The elevation above sea level is from 4,000 feet on the prairie to 10,000 foot peaks in Glacier National Park. Approximately 870 square miles of the eastern half of Glacier National Park lie within the station area. The St. Mary canal system runs from Babb, MT, to near Del Bonita along the station's northern border for a distance of fourteen miles. A part of the Lewis and Clark National Forest is included in the station area, as is a part of the Bob Marshall Wilderness area.

The St. Mary station is the western-most station of the Havre Sector and is bounded on the north by seventy-seven miles of International Boundary from the Continental Divide to the eastern boundary of the Blackfeet Indian Reservation, on the west from the International Boundary one-hundred fifty miles south to Rogers Pass, on the south from Rogers Pass fifty miles northeast along U.S. Highway 200 to the junction of U.S. Highway 89, and on the east from the International Boundary at the eastern boundary of the Blackfeet Indian Reservation to U.S. Highway 89. The boundary then proceeds south along U.S. Highway 89 to the U.S. Highway 89 and 200 junction.