Boiling River Trail

Overview

A Yellowstone classic: this short, easy walk leads to a rare, legal soaking spot where a hot spring stream pours into the cold, fast Gardner River. The mix creates natural “hot tub” pockets—shift a foot or two and the temperature swings from toasty to brisk. Total distance is about 1.25 miles round trip (out-and-back) with roughly 50 feet of gain, so most people get from car to water in around 10 minutes each way.

What to Expect

The path follows the river to a rock-lined soaking area. At the source, the hot water can be extremely hot (roughly 113–140°F), but where it blends with the river it often settles near comfy soaking temps around 105°F. Finding your “sweet spot” is the game—current, river level, and where people sit all change the mix. Footing is uneven and slick in places; the current is noticeable, so move cautiously, especially with kids. Expect travertine formations and the unmistakable steam-meets-river scene that makes this place so beloved.

Conditions, Closures, and Best Time to Go

The Boiling River area often closes in spring/early summer when the Gardner runs high, and it generally operates during daylight hours when open. Late summer into early fall usually offers the calmest water and best soaking conditions. Crowds are real on warm afternoons—arrive early or later in the day for a better shot at parking and some elbow room.

Safety and Rules

Soak at your own risk. Do not touch the direct hot-spring flow—it can severely burn. Avoid submerging your head or inhaling thermal steam; organisms in thermal waters can cause serious illness. Rocks are slippery, and the river’s current can push you around—test footing before committing. Wildlife uses this corridor; give all animals space. Swimsuits are required. No pets or bikes on the trail. Leave the soap (even biodegradable), food, and drinks out of the water, and no nudity or alcohol. Pack out every scrap of trash.

Gear and Comfort Tips

Wear strapped water shoes or sturdy sandals—flip-flops get swept away and bare feet regret the sharp, slick rocks. A small towel and a quick-dry layer make the walk back nicer. Plan to change at the trailhead; there are bathrooms, and benches near the soaking area are handy for stashing layers.

Parking and Navigation

Parking is limited—typically small lots on both sides of the road near the bridge along Highway 89 by the 45th Parallel area between Gardiner and Mammoth. It’s not heavily signed. Don’t rely solely on GPS inside the park; use official park maps and confirm with rangers. When in doubt (especially before midsummer), check the status at Mammoth Hot Springs before going.

Accessibility Notes

The first 50 yards are compact and accessible, but beyond that the surface becomes rocky and eroded with occasional short hills up to about a 20% grade. The final approach is a natural riverbank with uneven footing.