Sen. John Walsh (D), who was appointed to the seat vacated by Democrat Max Baucus, beat two challengers in Tuesday night's Democratic Senate primary, The Associated Press reports.
Walsh beat out rancher and former banker Dirk Adams and former Lt. Gov. John Bohlinger.
He will face off in November against Rep. Steve Daines (R) and libertarian Roger Roots.
Walsh's appointment to the seat by Gov. Steve Bullock (D) in February, when Baucus resigned to take a post as ambassador to China, gave the former lieutenant governor the advantage of incumbency.