Boulder Mountains

Rising north of Butte, east of Deer lodge, south of Hwy 12 between Helena and Garrison Jct. and west of the Jefferson City- Clancy area and the Boulder River Valley, the Boulder Mountains are one of the most historically significant range in the state of Montana owing to its mining history.

These mostly forest covered mountains hold a unique geologic structure, the Boulder Batholith. A batholith is a large mass of intrusive igneous rock, that made its way to the surface. While relatively small by world standards, the Boulder Batholith, and by extension the Boulder Mountains, contained almost unfathomable amounts of copper, gold, and silver. Vast deposits of theses minerals drove tens of thousands to Butte which eventually received the nickname, “the richest hill on Earth.”

Both the mountains and the batholith get their name from rounded granite boulders dotting the landscape. These are easily visible, especially crossing Homestake Pass along Interstate 90.

In the east, the Clark Fork River separates the Boulders from the Flint Creek Range. Upstream, the headwaters of the Clark Fork divide the Boulder Mountains from the Highland Range to its south. The Elkhorn Range, whose volcanic origins are associated with the Boulder Batholith, is split from the Boulder Range by the Boulder River.

Haystack Mountain on the Continental Divide, with an elevation of 8,819 feet is the highest peak in the range. At least three other peaks exceed 8,000 feet Jack Mountain at 8,752, Bull Mountain at 8,609 feet and Thunderbolt Mountain at 8,597 feet.

One of the most interesting places to visit in the Boulder Range is Ringing Rocks where the unique composition of the rocks found on the site creates a chime when tapped with a hammer. This attraction is accessible on the Eastern side of Homestake pass near Pipestone.

Numerous rivers and creeks with healthy, fishable trout populations like the Boulder River, Clark Fork River, and Silver Bow Creek get their start in or below the Boulder Mountains.

While the southern section of the range has been extensively mined, most of the Boulder Range is fairly remote with few trails. The most popular passage passing through the range is the Continental National Scenic Trail. The CDNST is easily accessed from McDonald Pass west of Helena and Homestead Pass east of Butte.

Blackfoot Meadows, also well-used is an easy 10.3 miles trail starting near Kading Campground along the Little Blackfoot River near Elliston. The trail follows numerous meadows traversing topography typical of that of the entire range.

Aside from outdoor recreation, there is an extensive historical record in the southern section of the range. The area has stories to tell for almost any historical interest. The early chronicles of Montana were largely driven both politically and economically by the significance of Butte just below the southwest corner of the Boulder Mountains.

For maps and other information of the Boulder Mountains contact the Butte Ranger District: (406) 494 – 2147  https://www.fs.usda.gov/bdnf.