To Beat The Heat, Yellowstone Grizzlies Jump Into ‘Bear Bathtubs’

Summer isn’t all fun and relaxation for Yellowstone’s bears, they’re busy packing on fat for the winter, which makes them heat magnets. So, they jump into “bear bathtubs” to cool off.

Mark Heinz

April 19, 20244 min read

Bears don’t sweat, so they must use small pools in isolated parts of Yellowstone National Park to cool off during the summer.
Bears don’t sweat, so they must use small pools in isolated parts of Yellowstone National Park to cool off during the summer. (Courtesy Kerry Gunther, National Park Service)

Being a bear in Yellowstone National Park on hot summer days can be downright miserable.

Bears are natural heat magnets, and they can’t sweat. As with dogs, panting is their only option. And frequently, that’s just not enough.

“Bears, just by the way they’re built, they retain heat. They have thick fur, and their fur is usually dark, so it absorbs heat,” Yellowstone bear management biologist Kerry Gunther told Cowboy State Daily.

To make matters worse, black bears and grizzlies alike are trying to pack on as much fat as possible in preparation for winter hibernation.

And all that fat retains even more heat, Gunther said.

So, what’s a poor overheated bear to do?

Luckily, remote areas of Yellowstone are dotted with small ponds and sinkholes that fill up with cool water and become “bear bathtubs,” so to speak.

“These little places where they cool off” attract lots of bears during the summer, Gunther said.

The bears will plop down inside them to soak, take long drinks or even swim about the larger ponds.

The National Park Service won’t disclose the exact location of any of these favorite bear lounging areas. The secrecy protects the bears from being harassed by gawking humans, and also keeps foolhardy people safe from bears that would rather not have their bath time interrupted.

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Usually Near Food Sources

National Geographic a few years ago set up a remote camera near a bear bathtub and caught some fantastic — and at times even hysterical — video of bears putting it to use.

At the end of the video, a large grizzly stops to check the camera out, starts fiddling with it and eventually knocks it over.

Gunther said he knows of the site where that video was taken. It’s near some stands of white bark pine trees. And during years when the trees are especially productive, bears will congregate there to gorge on white bark pine nuts, which will really fatten them up.

And during those years, that particular tub will likewise draw lots of bears.

Proximity to a food source makes for a good bear bathtub, because the bruins can alternate between eating and taking dips to cool off, he said.

The bear bathtubs aren’t used frequently during June and July, even though July is typically the hottest month in Yellowstone, Gunther said.

During the earlier summer months, bears are still relatively lean and can find other ways too cool off.

“They’ll dig pits and lay down in the cooler dirt in the shade,” he said.

It’s usually during August and September, when the bears are really starting to get fat, that the bathtubs get the most use.

Whose Turn Is It?

The bears also favor ponds that are isolated and tough to access to avoid human interference.

The bears in the National Geographic video might seem relaxed, but Gunther said bears are actually on high alert when they’re bathing.

They’re listening for people approaching, of course, and they’re also keenly aware of other bears.

Any bear is free to use the bathtub — until a bigger, meaner bear shows up.

“They work out a pecking order,” Gunther said. “The ones lower on the pecking order will run pretty quickly when a more dominant bear shows up.”

The National Geographic video at one point shows a black bear plunging into the pool, then immediately scrambling out and running away.

That’s typical of black bear behavior if they sense a grizzly approaching, Gunther said. Being the smaller species, black bears avoid confrontations with grizzlies.

“Black bears and grizzlies both use these ponds. It takes a little bit of time to jump out of the water, so black bears are always ready to jump out and run when a grizzly shows up,” he said.

No People Problems Yet

So far, there haven’t been instances of humans having run-ins with bears at any of the bathtubs, Gunther said.

Most conflicts between humans and bears in Yellowstone are along hiking trails, or when bears are actively feeding and distracted, he said.

It’s hoped the isolated bear bathtubs stay out of sight, out of mind for the vast majority of Yellowstone’s tourists, Gunther said, because they bears rely on them so heavily as temperatures soar.

Mark Heinz can be reached at

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Mark Heinz

Outdoors Reporter