Links to Montana government agencies, statutes, bills, cases and other primary legal materials are posted by the University of Montana law library, the State Law Library of Montana and FindLaw. Primary legal materials are also available from Lexis, Westlaw and Loislaw. Subscription services Versuslaw Fastcase have cases back to 1950; Google Scholar has cases back to 1950 for free. Fastcase has the Montana Code. Supreme and appellate court cases are published in the Pacific Reporter.
To check on the status of pending bills, call the Montana Legislative Session at 406-446-4800 or 406-444-3064.
For an overview of Montana legal research materials, see "A Complete Guide for the Montana Attorney," 24 Montana Lawyer 25 (you can get the article from Westlaw using the format "24-MAY MTLAW 25").
For questions about Montana legal materials, copies and/or inter-library loan, try calling the State Law Library of Montana (800-710-9827 in Montana; 406-444-3636 outside Montana) or the University of Montana's law library (406-243-6171).