File:M 4511125 ne 12 060 20210924.tif — public domain
Potosi Hot Springs flows at 122°F at 6,069 feet elevation in Madison County, Montana, making it one of the higher-elevation thermal sources in the state. The alkaline water registers pH 8.3 with 88 mg/L sodium and 98 mg/L sulfate, while calcium and magnesium are minimal. The spring sits just 17 meters from Willow Meadow Road with roadside access near Virginia City.
The spring emerges in the Tobacco Root Mountains at 6,069 feet, where subalpine meadows and dense conifer forests cover steep terrain above the Madison Valley. Annual precipitation reaches nearly 26 inches with about 65 inches of snow, and the average annual air temperature is just 38.8°F, among the coldest settings for Montana thermal springs. Willow-lined meadows occupy the drainage bottoms, giving the road its name. The surrounding country is rugged and sparsely populated.
History of Potosi Hot Springs
The Potosi name references the mining legacy of Madison County, echoing the famous Potosi silver mines of Bolivia, a naming convention common in 19th-century Western mining districts. Virginia City, the nearest town, served as Montana's territorial capital during the 1860s gold rush. The spring's proximity to these historic mining camps suggests it was known to early prospectors and settlers working the Alder Gulch placer deposits.
The 6,069-foot elevation means cool temperatures year-round, with an average of 38.8°F annually. Snow closes many area roads by late fall; confirm Willow Meadow Road is passable before driving in. The 122°F source water requires caution. Red Mountain Campground on the lower Madison River, reservable May through mid-September, sits about 26 km away. Virginia City's preserved ghost-town buildings make a worthwhile side trip.
Is Potosi Hot Springs worth visiting?
Best for
- Hot spring soaking
- Easy day trips
- Overnight camping trips
- Winter soaking with dramatic temperature contrast
Potosi Hot Springs offers an accessible hot spring experience — great for a day trip.
Annual Precip: 25.8 in
Annual Snow: 64.5 in
December
Air 17°F · Water 122°F · +105° contrast
January
Air 18°F · Water 122°F · +104° contrast
February
Air 18°F · Water 122°F · +104° contrast
December offers 48°F more contrast than July
Recent Temperature
55.4°F
(13.0°C)
Measured Jan 15, 1977
The water at Potosi Hot 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
61 miles from Virginia City, MT
USGS Quad: HARRISON 15 · PP 492: 31.0 · NOAA: 3.0 · AMS Map: BOZEMAN
What is the water temperature at Potosi Hot Springs?
Potosi Hot Springs has a water temperature of 122°F (50°C). This is considered a hot spring, well above body temperature.
Where is Potosi Hot Springs located?
Potosi Hot Springs is located in Madison County, Montana at 6,069 feet elevation, near Virginia City. Coordinates: 45.5900°N, 111.8990°W.
How do I get to Potosi Hot Springs?
Potosi Hot Springs has Roadside road access, with the nearest road being Willow Meadow Road (56 ft from the road).
Can I camp near Potosi Hot Springs?
Yes, Red Mountain (Mt) is located nearby (16.0 miles away).
What minerals are in the water at Potosi Hot 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 Hot Springs?
At 122°F, Potosi Hot 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 Hot Springs crowded?
Potosi Hot Springs is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to Potosi Hot Springs?
Essentials for Potosi Hot 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.