Potosi Warm Springs
Potosi Warm Springs discharges at 124 degrees Fahrenheit from alkaline waters (pH 8.3) with high sodium (88 mg/L) and sulfate (98 mg/L) concentrations. Located at 6,043 feet in Madison County, Montana, the spring sits 110.6 meters from Willow Meadow Road, classified as a short-walk access point near Virginia City.
The spring emerges in the upper Madison River drainage at over 6,000 feet, surrounded by montane meadows and conifer forest typical of southwestern Montana's high valleys. Annual snowfall reaches 64.5 inches and average air temperature sits at 38.6 degrees Fahrenheit, creating long, cold winters. Willow Meadow Road provides the nearest vehicle access, and the broader landscape is shaped by the same geothermal system that feeds other thermal features in the drainage.
Documentation on Potosi Warm Springs is limited. The spring shares its name with the nearby Potosi mining district, a reference to the famed Bolivian silver city, reflecting the area's 1860s mining heritage tied to the Virginia City gold rush. Madison County's thermal springs were cataloged in the 1980 NOAA/NCEI survey. Current development status and formal public access arrangements are not well documented.
Visit between late June and September, after snowmelt clears Willow Meadow Road. The 110-meter walk from the road is straightforward but unmarked. Water temperature at 124 degrees Fahrenheit can cause scalding; test carefully before contact. Red Mountain Campground, 25.7 kilometers away, accepts reservations from May through mid-September. Bring layers for cool mountain evenings at 6,000 feet.
Is Potosi Warm Springs worth visiting?
Best for
- Hot spring soaking
- Overnight camping trips
- Winter soaking with dramatic temperature contrast
The water at Potosi Warm Springs is slightly alkaline (pH 8.3).
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Overview The Dillon Field Office is unable to make reservations for you. Please call Recreation.gov (877-444-6777) to book a reservation or book online. Campsites are available for reservation for the Peak-Season times of May 1st through September 15th. From September 16th through April 30th, all sites are first-come-first-serve. Red Mountain Campground is adjacent to the lower Madison River and provides good access for camping, fishing and floating. The campground has 19 camp sites, 11 ava...