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Boiling River Trail



1.3 mile 2.1 kilometer out and back
100% Runnable


Ascent: 49' 15 m
Descent: -49' -15 m
High: 5,679' 1,731 m
Low: 5,636' 1,718 m


Avg Grade: 1% (1°)
Max Grade: 4% (2°)


No Dogs
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Trail shared by Tom Carter

Grab your swimsuit and towel and come soak in the warm pools at the edge of the Gardner River!

Tom Carter

Features Birding · Fall Colors · Hot Spring · River/Creek · Swimming · Views · Wildflowers · Wildlife

Boiling River is open during daylight hours only; swimsuits required. It may be closed in early summer due to high water; check first. The path comes close to Boiling River spring. Although it's not actually boiling, it's extremely hot. Stay on the path to avoid scalding. Many thousands have safely enjoyed swimming in the river pools warmed by the hot spring, however, hydrothermal waters can contain organisms that cause skin rashes or worse. Do not drink the water or dunk your head under it.


Grab your swimsuit and towel! This short, flat trail leads to one of the only legal swimming areas in Yellowstone. Come soak and relax at the edge of the Gardner River where water from the Boiling River hot spring mixes with cold river water. The trail is open daylight hours year round. Yes - year round. I once enjoyed swimming here at 15 below zero, during an especially chilly winter cold snap!

Need to Know

Bathing suits are required; alcohol is prohibited. There are no lifeguards on duty and the current of the river can be swift. All soaking is undertaken at the visitor's own risk.


The trailhead for Boiling River is found between Mammoth Hot Springs and the North Entrance Gate, where the road crosses the Gardner River. Swimming at Boiling River is a popular tradition. The parking lot on the east side of the road is often full and overflowing, as is the annex parking on the west side. There are small bathrooms near the trailhead that can be used for changing.

The trail heads south from the parking area and follows the Gardner River upstream. The river was named for Johnson Gardner, who trapped beaver in the area in the 1830s. The large trees along the trail are Black Cottonwood, one of the tallest, fastest-growing hardwood trees in the western United States. It is common along rivers and streams in the west, but rare in Yellowstone because of its high elevation. Mature cottonwoods attain heights of 125 to 150 feet and diameters of 48 to 60 in. Cottonwoods mature as early as 60 years and live at least 200 years.

As you head out along the wide, easy path watch for osprey (or fish hawks) or even bald eagles patrolling up and down the river looking for a meal of brook trout. After a pleasant 1/2-mile jaunt along the river, the trail reaches Boiling River hot spring. This spot is also marked by large clouds of steam, especially in cold weather. The trail loops around the 145-yard long “river.” At 6 to 9 feet wide and 2 feet deep, Boiling River is one of the largest discharging hot springs in the park.

The hot spring water mixes with the cold river water along the river's edge. Small rock walls have been built-up to form a number of soaking pools. Pick one that suits your taste! Until the 1980s, this wonderful soaking spot was unknown to most visitors and provided a late-night “hot potting” spot for park employees and residents of Gardiner, Montana. Bathers parked on the side of the road just above and scrambled down the hill to swim. Nudity and alcohol were common. To provide a safe place to park and easer access, the Yellowstone Park Foundation funded the Boiling River Trail Project, creating the parking areas and trail today enjoyed by many thousands of visitors. New rules also were constructed prohibiting nudity, alcohol, and nighttime swimming.

Once you’ve “taken the waters” of Boiling River, return to the trailhead along the same route you used to access the springs.

Thanks to guidebook author, Tom Carter, for sharing this trail description. To learn more about visiting Yellowstone, check out his book, Day Hiking Yellowstone.

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Trail Ratings

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29 Views Last Month
1,933 Since Sep 8, 2015



Boiling River bathers enjoy the many warm pools along the Gardner River.
Apr 24, 2016 near Mammoth…, WY
Winter soaking at Boiling River.
May 2, 2016 near Mammoth…, WY
The Boiling River is often accompanied by gorgeous wildflowers.
Jan 18, 2017 near Mammoth…, WY
Boiling river trail!
Mar 31, 2016 near Gardiner, MT
The Boiling River is quite a sight for both young and old alike.
Jan 18, 2017 near Mammoth…, WY
Enjoying a dip in the Boiling River.
Apr 25, 2016 near Mammoth…, WY


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