Our local avalanche center hosts avalanche courses throughout the month of January up at Buck Ridge Trailhead. They have Montana Alpine Guides host the event. Below is a link to sign up and register for the event.
Avalanche1 is brought to you by the American Avalanche Institute. They hold courses in several different states but here is the link to the courses they host in Bozeman and how to register.
The guys down at Ride Rasmussen Style down in West Yellowstone have put together several clinics throughout the year that can get you certified in AIARE. They have women's only, as well as couples courses too! Below is the link to register for one of their clinics.
Mike Duffy hosts and instructs Avy 1 courses all over the country and even hosts them around the UP for those that are going to travel out west. Although he does not host courses in Montana currently he does host them in Wyoming, Colorado, Iowa, Minnesota, Nebraska, North Dakota, Utah, and Wisconsin.