Marmots Are Waging War on Hikers in Sequoia National Park

Quick Facts: Marmots Terrorizing Sequoia National Park Hikers

• Yellow-bellied marmots are large ground squirrels that can grow to the size of a small dog

• Mineral King Valley, a remote 7,800-foot-high area of Sequoia National Park, is their unofficial headquarters

• Marmot season peaks from May to mid-July, when the animals swarm trailheads and parking lots

• One hiker's tow bill hit more than $1,000 after a marmot disabled his car's engine

• Marmots chew through radiator hoses, brake lines, and electrical wiring in search of salt and fluids

• The National Park Service recommends wrapping entire vehicles in plastic tarps, including the wheel wells

• Chicken wire no longer works as a defense, since marmots have reportedly learned to get around it

• Some marmots have hitched rides in car engines all the way to Southern California

Meet the Yellow-Bellied Marmot, Sequoia's Least Welcome Local

Marmots are ground squirrels, not the tree-climbing kind, and the yellow-bellied variety found in Sequoia and Kings Canyon National Parks has apparently decided that cute and menacing are not mutually exclusive. They're common at higher elevations throughout the parks, but Mineral King Valley is where the real chaos happens. It's remote, popular with backpackers, and full of marmots who seem to have figured out that human gear is basically a buffet.

What makes them so bold isn't hunger in the traditional sense. Rangers and researchers point to their appetite for salt, which helps explain the fascination with sweaty hiking boots, backpack straps, and anything else that's had prolonged contact with a human. Once a marmot decides your shoe smells promising, negotiations are basically over.

The Gear Heist Stories Are Genuinely Wild

Some hikers have learned to take extra precautions at camp after run-ins with the local marmots. One reportedly started tying his shoes together after a marmot made off with a single boot, which was later found stashed behind a log. Another watched a marmot steal a trekking pole, then charge when someone tried to take it back. The hikers ultimately decided the marmot had won custody of the pole.

And then there’s perhaps the most unsettling encounter of all: a hiker who dozed off on a mountain pass and woke up to a marmot licking his ear. His reaction was, understandably, somewhere between horror and disbelief. You go to Sequoia expecting giant trees and sweeping mountain views, not to wake up being gently tasted by wildlife.

Your Car Isn't Safe Either

If gear theft feels manageable, the parking lot situation is where things get expensive. Marmots crawl underneath vehicles and into engine compartments, where they chew through plastic, radiator hoses, brake lines, and wiring while lapping up antifreeze and other fluids. One unlucky hiker paid over $1,000 to get towed down the narrow, winding mountain road after a marmot left his car undrivable.

The Park Service's current advice sounds almost absurd until you realize how serious it is: drive onto a tarp, then wrap the entire vehicle in it, wheel wells included, essentially diapering your car for the day. Chicken wire used to work as a barrier, but marmots have apparently adapted and now climb around it.

There are even reports of marmots hitching unintentional rides inside engine compartments all the way to Southern California, which is either terrifying or the most impressive commute of any rodent in America.

How to Actually Protect Yourself (and Your Car)

• Tie your shoes together or keep them inside your tent rather than outside

• Never leave backpacks, trekking poles, or salty gear unattended at a trailhead

• Wrap your entire car in a tarp, including underneath and the wheel wells, before leaving it parked for the day

• Skip the chicken wire, since marmots have reportedly figured out how to bypass it

• Check under the hood before starting your car if you've parked in Mineral King Valley for more than a few hours

• Keep a respectful distance if a marmot approaches, since some have charged hikers over stolen items

A vehicle wrapped in a tarp to keep curious marmots from crawling inside. Photo Courtesy: National Park Service (NPS)/Jennifer Swacina

So, Should You Still Go?

The chaos isn't random. Marmot mischief tends to peak from May through mid-July, when the animals are most active around trailheads and parking areas, likely on the hunt for salt, food scraps, and anything else visitors have conveniently left behind. In other words, if you're heading to Sequoia or Kings Canyon in early summer, you're visiting during prime marmot season.

The behavior itself isn't exactly new, but it does seem to be getting bolder. Marmots have always lived in these parks, but with more visitors arriving each year, along with hiking boots, backpacks, cars, and gear pre-seasoned with sweat and snack crumbs, they've apparently gotten very good at figuring out where the easy wins are.

None of this means you should skip Sequoia. It just means packing a tarp along with your hiking boots and treating every marmot like it's already plotting something. The giant sequoias are still some of the most awe-inspiring sights in California, marmots or not. Just keep an eye on your gear, protect your car, and maybe don't fall asleep anywhere a marmot can reach your ear.

Frequently Asked Questions: Marmots in Sequoia National Park

Why are marmots attacking cars in Sequoia National Park?

Marmots are drawn to the salt and fluids found in vehicles, including radiator hoses and brake lines, and they chew through wiring and plastic to get to them, sometimes disabling the car entirely.

When is marmot activity worst in Sequoia National Park?

Marmot mischief peaks from May through mid-July, when the animals are most active around trailheads and parking lots.

Where in Sequoia National Park are marmots the biggest problem?

Mineral King Valley, a remote area of the park at around 7,800 feet elevation, is considered the epicenter of marmot-related trouble.

How do rangers recommend protecting a car from marmots?

The National Park Service advises driving onto a tarp and wrapping the entire vehicle in it, including the wheel wells, since marmots can climb underneath and into engine compartments.

Does chicken wire protect cars from marmots?

No. The Park Service no longer recommends chicken wire, since marmots have learned to maneuver around it.

Are yellow-bellied marmots dangerous to humans?

They aren't typically dangerous, but some have charged hikers who tried to retrieve stolen gear, so keeping a respectful distance is smart.

Can marmots actually steal hiking gear?

Yes. Hikers have reported marmots stealing shoes, backpacks, and trekking poles, likely because of the salt residue from sweat.

Should I still visit Sequoia National Park because of the marmots?

Absolutely. The marmots are a quirky hazard, not a reason to skip one of California's most spectacular national parks, as long as you take basic precautions.