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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.
History of Potosi Warm Springs
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
Potosi Warm Springs is well suited for hot spring soaking and overnight camping trips.
Annual Precip: 25.8 in
Annual Snow: 64.5 in
December
Air 17°F · Water 124°F · +108° contrast
January
Air 18°F · Water 124°F · +106° contrast
February
Air 18°F · Water 124°F · +106° contrast
December offers 49°F more contrast than July
Recent Temperature
55.4°F
(13.0°C)
Measured Jan 15, 1977
The water at Potosi Warm Springs is slightly alkaline (pH 8.3).
pH influences mineral absorption through skin
May support bone density and joint health
Known for muscle relaxation and stress relief
Supports circulation and skin hydration
Traditionally used for skin conditions and inflammation
Natural antiseptic with skin health benefits
Iron-rich springs may support circulation
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...
Reserve on Recreation.gov →
Swimsuit & towel
Water bottle
Stay hydrated, especially in hot water
Warm layers
Cold air before and after soaking
Camping gear
Nearby camping at Red Mountain (Mt)
Trash bag
Pack out what you pack in
Water shoes
Hot ground near source
62 miles from Virginia City, MT
USGS Quad: HARRISON 15 · NOAA: 2.0 · AMS Map: BOZEMAN
What is the water temperature at Potosi Warm Springs?
Potosi Warm Springs has a water temperature of 124°F (51°C). This is considered a hot spring, well above body temperature.
Where is Potosi Warm Springs located?
Potosi Warm Springs is located in Madison County, Montana at 6,043 feet elevation, near Virginia City. Coordinates: 45.6020°N, 111.9000°W.
How do I get to Potosi Warm Springs?
Potosi Warm Springs has Short Walk road access, with the nearest road being Willow Meadow Road (363 ft from the road).
Can I camp near Potosi Warm Springs?
Yes, Red Mountain (Mt) is located nearby (16.0 miles away).
What minerals are in the water at Potosi Warm Springs?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 8.3 (slightly alkaline).
Is it safe to soak at Potosi Warm Springs?
At 124°F, Potosi Warm Springs is hot enough to require caution. Enter slowly, limit soaking sessions to 15–20 minutes, and stay hydrated. Access may be on private land or unconfirmed — verify current conditions before visiting. Always tell someone your plans before visiting remote hot springs.
Is Potosi Warm Springs crowded?
Potosi Warm Springs sees varying levels of visitors depending on the season and day of the week.
What should I bring to Potosi Warm Springs?
Essentials for Potosi Warm Springs: swimsuit, towel, water bottle, warm layers for before and after soaking, camping gear, a trash bag to pack out what you pack in. The water is over 110°F — test the temperature before entering and watch for scalding near the source.