Most listings are in the $10's per square foot per year. The Montana region is going through a a boost in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 6% increase in rent.
In the last 90 days, 229 listings have been listed, so you'll want to check back regularly for new listings. About 0% of the office spaces in the Montana are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,900 sqft. Most properties in this area are approximately 2 floors. Most buildings in this market were built in 1984 and are Class A.