Swimming might not sound like the top thing to do in Yellowstone National Park. Yet, it was a very quiet and relaxing time during our trip to the park and a fabulous way to cool off from the heat in early September.
You better not go swimming “anywhere” in Yellowstone. Hot springs are boiling hot and mountain rivers are cold, many of them have strong currents.
There are two designated places to swim, dip or soak in Yellowstone National Park: Firehole River Swimming Area and Boiling River Swimming Area. Make sure to check the hours on the local website before you go. (Both areas remained closed due to coronavirus pandemic when I was writing this post).

Boiling River Swimming Area: Soak or Take a Dip
Despite the official name “The Boiling River Swim Area” there is no actual swimming in Boiling River: it is boiling hot. But once it flows into Gardner River, the two are mixing up and create sort of hot spring where you can soak or take a dip.
Location
Boiling River Swimming Area is just 5 minutes away by car from Mammoth Hot Springs. There is a general store, cafe, and some picnic tables to have lunch before/after swimming in Boiling River.
Mammoth Hot Springs Mammoth Hot springs terraces
Boiling River parking lot (44.9924785,-110.6936553) is limited: only 46 spots. Half of them located directly at the swimming area trailhead (on the picture below) and the other half is across the road.

On the Trail
The trailhead starts right on the border between Wyoming and Montana. The half-mile trail starts with these signs:
Entering Wyoming Sign Entering Montana Sign
The trail is easy but has no shade. Grab sunscreen on a hot sunny day, as well as plenty of water, bathing suits, and towels.
We saw families coming in full gear: in water shoes, with lifesaving vests on kids. We were curious why, until we reached the place:

Beware of Current if Coming with Little Ones
The water current is so strong, that you’ll have to hold little children (3-4 y.o.) by their hand really tight when walking to the bathing area.
Water shoes are a great idea: footing is slippery and with rough stones at the Gardner River. If you drop your crocks or flip-flops, you won’t have a chance to retrieve them because of the fast current. We decided to keep our 15-months-old out this time – it was too much.
As you can see in the picture below, there is no actual “swimming” at Gardner River – the water is about knee-deep in most places.

Water is pleasant but constantly changing from warm to hot, and too cold. I loved it and would stay there much longer if we would be without little ones.
“Kiddie area” at Gardner River: the water is more than shallow. And cold, but refreshing.

A group of Roosevelt Elks was bathing nearby, paying almost no attention to human beings around:

Firehole River Swimming Area
Just 2 minutes before you reach the Firehole River Swimming Area, there is the Firehole Falls. A quick pleasant stop with small parking across the road.

To reach the Firehole River shore, we parked along the road and made a very short hike downhill to get to the water.

Compared to Boiling River, Firehole River was a completely different experience: everybody could swim here. The footing is much pleasant – mostly sand.

The water was crystal clear and chilly. You may notice the current running right in the middle of the river in the picture below. Our grandpa dared to swim it across and back:

If you are ready for lunch, in 7 minutes by car is a nice picnic area near the river – Nez Perce (44.578803,-110.831611). There is a lot of space to run around if you or kids still have energy left 😉.


Have a great time at Yellowstone, friends!
Swimming in Yellowstone on My Maps
Read next: 11 Things We Learned Only After We Had Reached Yellowstone
10 Places you can’t miss on the way from Seattle to Yellowstone and back
Planning the Alaska road trip, on a budget, with kids. Glaciers, fjords, wildlife, National Parks, panning for gold, Alaska Native heritage, etc.