Visitor Information Jefferson County carries a feeling of the old west to those who visit. In the heart of Jefferson County is the county seat, Boulder. It is the state's 45th largest city with a population of about 1500.
Boulder is half way between the state capital of Helena and the mining town of Butte.
It is located on Interstate 15 at State Highway 69. Its quiet streets watch many visitors come to see the old buildings and artifacts from its boom time of the Late 1880's. Just off I-15 at exit 160 south of Boulder are the remote ghost towns of Comet and Gray Eagle. Each had an active mine for its support during their boom days. Many of these buildings are still in use.