The main local newspaper in Great Falls Montana is The Great Falls Tribune.  According to their website, they are the oldest business in Great Falls (122 years as of 2007) and they reach a 13 county area with a population in excess of 117, 000.

Mailing address:
205 River Drive South
Great Falls Montana 59405
Tel: 406-791-1444

Website: www.greatfallstribune.com