| February 22, 1889 25 Stat. 676 |
Congress organized Montana as one judicial district, authorized one judgeship for the U.S. district court, and assigned the District of Montana to the Ninth Circuit. The act became effective upon the admission of the State of Montana on November 8, 1889. |
| September 14, 1922 42 Stat. 837 |
One temporary judgeship authorized. |
| May 31, 1938 52 Stat. 584 |
Judgeship authorized in 1922 made permanent. |
| June 25, 1948 62 Stat. 895 |
Congress transferred the portions of Yellowstone National Park situated in Idaho and Montana to the District of Wyoming. |
| July 10, 1984 98 Stat. 333 |
One additional judgeship authorized. |