Most listings are in the $20's per square foot per year. The Missoula County submarket is going through a an increase in rates. In the last 3 months, the median rate increased $23 per sqft per year.
In the last 90 days, 63 listings have come on the market, so you'll want to check back regularly for new listings. About 84% of the available space in the Missoula County are subleases, so you might be able to find a shorter term or below market rent. 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 2,040 sqft. Most buildings in this region are close to 2 floors. Most buildings in this area were built in 1971 and are Class C.