The typical asking rate per listing is in the $10's per square foot per year. The Yellowstone County region is seeing a decrease in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 5% decrease in rent.
In the last 90 days, 38 listings have been made available, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. About 3% of the available space in the Yellowstone County are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 1,500 sqft. Most buildings in this area are close to 2 stories. Most buildings in this region were built in 1984 and are Class A.