Boulder Mountains (Montana)

The Boulder Mountains are a mountain range running north–south west of Boulder between Helena and Butte in the U.S. state of Montana. Parts of the range are in four different counties: Deer Lodge, Jefferson, Lewis and Clark, and Silver Bow.

Haystack Mountain, which reaches 8,819 feet (2,688 m), is the tallest peak in the range. The three other highest peaks are Jack Mountain at 8,752 feet (2,668 m), Bull Mountain at 8,609 feet (2,624 m), and Thunderbolt Mountain at 8,597 feet (2,620 m). All four peaks are in Jefferson County.