Official Records
The records of the U.S. District Court for the District of Montana are included among Record Group 21 and are split between the:
National Archives at Denver
Buildings 46 and 48
Denver Federal Center
West 6th Avenue and Kipling Street
Denver, Colorado 80225
Email: denver.archives@nara.gov
and the:
National Archives at Seattle
6125 Sand Point Way NE
Seattle, Washington 98115
Email: seattle.archives@nara.gov
Guides to the holdings of the regional archives are available at: https://www.archives.gov/denver/holdings/guide
and http://www.archives.gov/seattle/holdings/index.html
A published description of the records is also available in the Guide to Federal Records in the National Archives of the United States, 1995 (http://www.archives.gov/research/guide-fed-records/index.html ).