If you’re looking for a list of the undeveloped hot springs in Montana, then you’re in the right place.
A vast network of underground pockets, streams, and tunnels holding geothermal water stretches underground across western Montana, occasionally breaking through the surface, creating small pools perfect for soaking in.
These are Montana’s wild, undeveloped hot springs, featuring no manmade infrastructure, save for some fences, picnic tables, and restrooms at some locations.
Read on to discover the five best undeveloped hot springs in Montana. Find out how to get to them, what the atmosphere is like at each one, and tips for visiting each spot.
Before we begin…
Before we begin, we need to share two critical pieces of advice:
Don’t swim in undesignated hot springs. Seriously, it can be fatal. Even walking through areas with wild hot pots is dangerous, as you risk slipping and falling in.
Bring bear bells and bear spray. There is always a wild animal threat in the Montana backcountry. Always bring bear bells and bear spray with you when visiting undeveloped hot springs in Montana.
5 best undeveloped hot springs in Montana
Find all of Montana’s undeveloped hot springs on the map below.
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1. Nimrod Warm Spring
Rate
Free
Hours
Year-round, weather permitting, depending on road access.
Temperatures
70°F (21°C) year-round
Accommodation
None
Location
Roughly 35 minutes southeast of Missoula off Interstate 90.
Access
A half-mile walk from the nearby parking lot.
Pets
Dogs are forbidden from entering the water and must be leashed.
Details
Nimrod Warm Springs features no manmade constructions. This is a large, clear, natural pool of warm water, fed by an uphill spring. The pool itself is deep and best suited for experienced swimmers.
The water in Nimrod Warm Spring is a crystal clear, bright blue color. With slightly cooler waters and views of the surrounding Snowcrest and Little Belt Mountains, Nimrod Warm Spring is perfect for hot summer afternoons.
*The water is warm, not hot. Because of its large size, the water is much cooler than the water in other undeveloped hot springs in Montana. The water here sits at about 70°F (21°C) year-round. If you’re looking for hot waters, move on to #2 on this list.
A special request from the owners
The owners of the property on which Nimrod Hot Springs is located recently noticed an increase in trash left behind by swimmers. To keep this undeveloped Montana hot spring open, the owners ask you to pack out anything you pack in.
Find Nimrod Warm Spring on the map
2. Boiling River
*Due to 2022 flooding on the Gardner River, the Boiling River Hot Spring is indefinitely closed
Rates
Free
Hours
- Early Jul – Early Sep: 6 am – 8 pm
- Fall/Winter/Spring: 7 am – 6 pm
Temperatures
Hot spring water emerges at 140°F (60°C) and mixes with cold river water, making for ideal bathing temperatures, but we don’t have the exact temperature measurements.
Because of this constant circulation of hot and cold water, the water temperature at Boiling River Hot Springs fluctuates, though remains comfortable.
Accommodation
None
Location
The Boiling River Hot Springs is actually located in Wyoming, just across the Montana-Wyoming border. It lies 20 minutes south of Gardiner in Yellowstone National Park on the North Entrance Road.
Access
Visitors can find parking spaces on either side of the North Entrance Road.
Pets
Dogs may not enter the water, and they must be leashed.
Details
Boiling River Hot Springs is one of the only undeveloped hot springs in Yellowstone National Park that the public can soak in. While this is a wild, undeveloped hot spring with no concrete pools or other manmade infrastructure, it is a well-known hot spring and sees lots of traffic in the summer.
When you visit the Boiling River Hot Springs in Montana you will immediately understand why it’s so popular. Located on the Gardner River, this undeveloped hot springs in Montana offers bathers a pleasant atmosphere with incredible views of the surrounding hillsides of the Gallatin Range.
The pool
People have stacked rocks up along the banks of the Gardner River to trap hot water flowing from the Boiling River into the Gardner River. These makeshift rock walls form the hot pots that you soak in.
Cold and warm water regularly circulates through these rock walls, resulting in fluctuating water temperatures. However, the water generally remains steady and hot.
Check Boiling River water temperatures at waterdata.usgs.gov.
Looking for a nearby hotel?
The nearest town is Gardiner, a charming town on the banks of the Yellowstone River that offers various accommodation options.
Find Boiling River Hot Springs on the map
3. Gigantic Warm Spring
Closed? According to Google, Gigantic Warm Spring in Montana is permanently closed. Also, we couldn’t find their Facebook page, which seems to have been active several years ago, so it may be true. However, it’s worth knowing it’s there, just in case.
Rate
- Age 14+: $4
- Age 6 – 13: $3
- Age 0 – 5: Free
Hours
12 pm – 9 pm daily, from early June to Labor Day (early September)
Temperature
68°F (20°C)
Accommodation
- RV pitches: $15/night
- Tent camping: $15/night
Location
About 20 min (15 mi) northwest of Lewistown on MT 81.
Access
On-site parking lot
Pets
Not allowed
Details
Unlike the other undeveloped Montana hot springs on this list, Gigantic Warm Spring offers a few manmade amenities, including an on-site parking lot, picnic tables, and a wooden boardwalk along the water’s edge for sitting and relaxing by the water.
The pool is surrounded by green grass in a beautiful valley between the North and South Moccasin Mountains in Fergus County.
We haven’t checked the statistics, but Gigantic Warm Spring claims to be the largest warm spring in the world, with roughly 50,000 gallons (19,000 liters) of natural spring water flowing from it each minute.
This enormous pool of fresh, rejuvenating water, surrounded by greenery and mountain views is the perfect place to cool off on a hot summer day in Montana.
*The water is warm, not hot. Due to its large size, Gigantic Warm Spring is much cooler than other undeveloped hot springs in Montana. Water temperatures here remain at around 68°F (20°C) year-round.
Find Gigantic Warm Spring on the map
4. Renova Hot Springs
Rate
None
Hours
Year-round
Temperature
110 – 122°F (43°C – 50°C) at the source
Accommodation
None
Location
About 10 min (10 mi) by car south of Whitehall on MT 81
Access
On-site parking
Pets
Dogs are forbidden from entering the water and must be leashed.
Details
Like the Boiling River, Renova Hot Springs takes advantage of a hot spring flowing into the banks of a river.
The pools here are located along the banks of an estuary of the Jefferson River. The pools are formed by rock and cement walls that collect warm hot spring water flowing from the bank.
Renova Hot Springs is located in a valley between the Highland and Tobacco Root Mountains, offering splendid views to anyone who ventures out here.
The best time to go and how to get there (it washes out in spring)
The road to this undeveloped Montana hot springs is rough and requires a 4×4 vehicle. In cold and wet months, when there is moisture and snow on the ground, the road to the hot springs is impassible.
Also, because these soaking pots lie on a riverbank, they usually get washed out in the spring runoff, making the entire site inaccessible.
The best time to visit Renova Hot Springs is between July and October after the spring water levels have dropped and the river is calm. Check the Jefferson River water levels using the USGS gauge at the Parsons Building near Silver Star, Montana. The ideal water level for soaking is around 700 cfs.
Find Renova Hot Springs on the map
5. Upper Potosi Hot Springs
Rates
Free
Hours
Year-round, weather and road conditions permitting.
Temperatures
90° – 99°F (32° – 38°C)
Accommodation
Camping is available at Potosi Campground, located at the trailhead.
Location
About an hour by car south of Butte, Montana, on Potosi Rd in the Tobacco Root Mountains.
Access
Park at the nearby Potosi Campground and Picnic Area and walk 20 minutes (1.5 miles) to the hot spring.
Pets
Dogs must be leashed and shouldn’t go in the hot springs.
Details
Upper Potosi is a quaint little hot pot with rock walls and a gravel bottom, tucked away along South Willow Creek, in southwestern Montana.
Water bubbles up and flows down a hillside into the pot. A second source seeps up from the gravel bottom. A fence around this undeveloped Montana hot spring keeps cattle and other animals from the water.
Upper Potosi Hot Springs is one of the most charming undeveloped hot springs in Montana, a great choice for anyone looking to get close to nature. Come here, dip in, and let the waters do their magic.
An offroad adventure
The off-road portion of the journey to this undeveloped Montana hot springs has potholes and requires a 4×4 car with good clearance. Check the road conditions before you go.
*Not to be confused with Potosi Hot Springs. Upper Potosi Hot Springs and Potosi Hot Springs are two different establishments within one mile of each other in the same valley. Potosi Hot Springs is one of the best developed hot springs in Montana.
Find Upper Potosi Hot Springs on the map
Discover more Montana hot springs:
- 15 Best hot spring resorts in Montana
- 6 Best hot springs near Bozeman, Montana
- 13 Best hot springs near Missoula, Montana
- 7 best hot springs near Billings, Montana
- 6 best hot springs near Kalispell, Montana
- 5 best hot springs near Glacier National Park
- 8 hot springs in and near Yellowstone National Park
While the hot springs on this list are well-known and sometimes visited by the public, they are not managed by anyone or any official entity, so we can’t guarantee that they are safe to spend time at or swim in.
Conditions change daily in the Montana backcountry. Speak with regional authorities and check local weather conditions, water temperatures, and other relevant safety information before traveling to the locations on this list or getting in their waters. Swim at your own risk.
