Montana has a wide variety of information for visitors to the state. The state tourism board is known as the Montana Office of Tourism. The web site is www.visitmt.com, and their call center is 800-VISITMT. This is a great place to start looking for information about the state, as well as maps, lodging directories, calendars of events, etc. They also run a user-generated travel-planning site called Get Lost (in Montana) at GetLostMT.com.
In addition, the state is divided into six tourism regions who can provide more specific information about their respective areas.