When starting a new business, Montana does not require a general business license. Licenses will depend on your type of business and your local city and county requirements. You will need to contact your local city and county offices to find out what they require. The Montana Association of Counties is a good place to start, at (406) 449-4360, or http://www.mtcounties.org.
If your business is specific (but not healthcare-related) profession, you may need a professional license. The Montana Department of Labor & Industry/Business and Occupational Licensing Bureau will let you know. They can be contacted at (406) 841-2300 or http://bsd.dli.mt.gov/license/license.asp
For information on one-stop licenses, agricultural certifications, construction contractor registration, and independent contractor exemption certificate, the SBDC provides more information, on pages 10 and 11 of the following document: http://sbdc.mt.gov/Portals/131/shared/SBDC/docs/StartUpGuides/SmallBizStartUpGuide.pdf