Boulder Hot Springs has been operating since 1863 — which makes it one of the oldest continuously operating hot spring resorts in Montana. The main building, a Mission Revival structure built in 1893, is listed on the National Register of Historic Places.
The springs bubble up from the ground at 175°F and are cooled to usable pool temperatures. The town of Boulder surrounds it — the county seat of Jefferson County, sitting on the Boulder River between Helena and Butte on I-15.
TL;DR
- Boulder (~1,200) is the county seat of Jefferson County, on I-15 between Helena (33 miles north) and Butte (37 miles south).
- Boulder Hot Springs (1863, historic Mission Revival building) is the anchor attraction — natural geothermal pools in a National Register property.
- Elkhorn Ghost Town (12 miles southeast) is one of Montana’s most intact silver-boom ghost towns.
- The Boulder River provides fly fishing access through the valley.
- Best for: I-15 travelers wanting an authentic stop, hot spring seekers, ghost town enthusiasts.
Boulder at a Glance
| Population (2020) | ~1,200 |
|---|---|
| County | Jefferson County (county seat) |
| Region | Southwest Montana |
| Distance to Helena | ~33 miles north (~35 min) |
| Distance to Butte | ~37 miles south (~40 min) |
| I-15 exits | Exit 160–163 |
| Best for | Boulder Hot Springs, Elkhorn ghost town, I-15 road trip stop |
What Makes Boulder Different
Jefferson County was shaped by three things: the Jefferson River valley agriculture, the silver and gold mining in the surrounding ranges, and the I-15 corridor connecting Helena and Butte. Boulder sits at the intersection of all three.
Boulder Hot Springs is the primary draw. The geothermal springs — discovered by miners in the 1860s — have been operated continuously for over 160 years. The current building dates from 1888–1893 and was Montana’s premier resort hotel in the late 19th century. Today it operates as a historic inn and day-use hot spring facility.
Elkhorn is the ghost town story no one tells. 12 miles southeast of Boulder via a gravel road, Elkhorn was a silver boom town of 2,500 people in the 1880s. Two Victorian dance halls — Fraternity Hall and Gillian Hall — still stand in remarkable condition, managed by Montana State Parks. Unlike Virginia City (still inhabited) or Bannack (completely empty), Elkhorn represents a middle state: buildings preserved but no residents, surrounded by forest, eerie and compelling.
For broader trip context, see my Montana cities and towns hub.
The Top 10 Things to Do
1. Boulder Hot Springs
Natural geothermal pools in a historic 1893 Mission Revival building — indoor and outdoor pools, day passes available. The building’s architecture alone is worth the visit; the pools are fed by springs that reach 175°F and are cooled for use. Lodging available in the historic building.
2. Elkhorn Ghost Town State Park
12 miles southeast on gravel road — two preserved Victorian dance halls (Fraternity Hall and Gillian Hall) standing in a forested mountain setting. Self-guided walking tour. Unlike most Montana ghost towns, the two main buildings are structurally intact and genuinely impressive. Free.
3. Boulder River Fly Fishing
The Boulder River flows through town — good brown and rainbow trout fishing in a working valley river. Less famous than the Madison or Beaverhead but locally productive. Multiple public access sites.
4. Jefferson County Courthouse
Boulder’s impressive 1881 brick courthouse — one of the finest surviving 19th-century county courthouses in southwest Montana.
5. Montana Developmental Center History
A significant state institution that operated in Boulder for over a century (1892–2015), the campus represents an important chapter in Montana’s institutional history.
6. Hike in the Helena National Forest (Elkhorn Mountains)
Multiple trailheads above Boulder in the Helena National Forest access the Elkhorn Mountains — the same range visible from Canyon Ferry Lake near Townsend.
7. Jefferson Valley Scenic Drive
The Boulder River valley south of Boulder through Whitehall — agricultural scenery framed by mountain ranges.
8. Day Trip to Helena (35 min)
State capital, Montana Historical Society, Last Chance Gulch. See Helena guide.
9. Day Trip to Butte (40 min)
Berkeley Pit, World Museum of Mining, Copper King Mansion. See Butte guide.
10. Ghost Town Loop Drive
Combine Elkhorn (12 miles SE) with a drive through the surrounding Elkhorn Mountains — connects to multiple Forest Service roads and abandoned mining sites.
Where to Stay
| Hotel | Vibe | Price | Best For |
|---|---|---|---|
| Boulder Hot Springs Inn | Historic, unique | $120–200 | Character, hot spring focus |
| Elkhorn Motel | Basic, affordable | $80–120 | Budget travelers |
| Helena/Butte options | Full selection | $130–250 | More variety |
Where to Eat
- Marysville House (Marysville, 30 min) — legendary Montana steakhouse in a ghost town setting
- Boulder Bar & Grill — local gathering spot
- Helena or Butte dining for more variety
Getting There
I-15 passes directly through Boulder. From Helena: Exit 160, 33 miles north (~35 min). From Butte: Exit 160, 37 miles south (~40 min).
Personal Tips
Elkhorn is the sleeper attraction. Most travelers bypass Boulder entirely and miss one of Montana’s most genuine ghost town experiences. Drive the gravel road.
Boulder Hot Springs for an I-15 break. Long I-15 drive between Helena and Butte? The hot springs make an excellent midpoint stop.
Check Boulder Hot Springs hours. They vary seasonally; call ahead to confirm day-use pool availability.
Quick Facts
| Founded | 1862 (mining camp) | | Boulder Hot Springs | Operating since 1863; National Register building (1893) | | Elkhorn | Peak population ~2,500 (1880s); two preserved dance halls | | Average summer high | 80°F |
Conclusion
Boulder is the I-15 stop between Helena and Butte that actually has substance. Boulder Hot Springs is a genuine historic hot spring resort; Elkhorn is one of Montana’s most compelling ghost towns; and the Jefferson Valley character makes it worth more than a highway sign. Stop.
Frequently Asked Questions
Is Boulder Montana worth visiting?
Yes — primarily for Boulder Hot Springs (a genuine historic geothermal resort operating since 1863, in a National Register 1893 Mission Revival building) and Elkhorn ghost town 12 miles southeast (two remarkably preserved Victorian dance halls in a forested mountain setting). As an I-15 stop between Helena and Butte, it’s the most substantive option on that corridor.
What is Elkhorn ghost town near Boulder Montana?
Elkhorn is a 19th-century silver mining ghost town 12 miles southeast of Boulder, managed as a Montana State Park. Two Victorian buildings — Fraternity Hall and Gillian Hall — are preserved in remarkably intact condition in a forested mountain setting. Free, self-guided walking tour. Accessible via gravel road from Boulder.
What is Boulder Hot Springs?
Boulder Hot Springs is a historic geothermal resort that has operated since 1863. The main building (1893) is a Mission Revival structure listed on the National Register of Historic Places. Natural springs reach 175°F and are cooled for indoor and outdoor soaking pools. Day passes and lodging are both available.
