Library of Congress links for research in Montana
http://www.loc.gov/rr/genealogy/bib_guid/states/mt/mt.html
National Archives – Rocky Mountain Region (Denver)
Colorado, Montana, New Mexico, North Dakota, South Dakota, Utah, Wyoming
http://www.archives.gov/rocky-mountain/
Montana Historical Society Research Center
Museum of the Rockies
http://www.museumoftherockies.org/
Montana State Genealogical Society
http://rootsweb.ancestry.com/~mtmsgs/
Western Montana Genealogical Society
http://www.rootsweb.ancestry.com/~mtwmgs/
Montana State Univ. Bozeman – Renne Library
University of Montana Mansfield Library
Montana State Library
Great Falls Genealogy Society