Butte Batholith: Helena to Butte Professional Review and Guide
"The 64-mile stretch of road between Helena and Butte goes through some mighty pretty country as Interstate 15 crosses over the Butte Batholith. This volcanic formation was created some 70 million years ago when lava shot up from the earth’s core. This phenomenon is responsible for the wealth of minerals in the area. At one time numerous mining towns flourished. Today a handful of small towns are located along the route, some only ghost towns.
The small town of Boulder is situated in an area that had successful mining operations at one time, including gold, silver, lead, and uranium. The large boulders in the area surrounding town explain how Boulder got its name. Several ghost towns remain in the area, the most well known being Elkhorn, now a state park. Boulder also has hot springs and radon mines, touted by many for having positive health benefits. There are facilities in Boulder where visitors can enjoy these offerings. This eTrail provides detailed information on family-friendly things to do. The destinations include: Boulder City Park, Boulder Hot Springs, Free Enterprise Health Mine, Elkhorn Ghost Town State Park, Bear Gulch Trail 123, and Cottonwood Lake Trail."