Yellowstone's mudpots are boiling hot, acidic and stinky – so why are tourists getting so close?

Boiling mudpot at Yellowstone National Park, Wyoming, USA
(Image credit: Getty)

Yellowstone National Park is home to a host of geothermal features, one of the strangest of which are the mudpots in the Mud Volcano Area. These pools of roiling mud are some of the most acidic features in the park, with a limited water supply and microorganisms that produce hydrogen sulfide gas and produce a distinctive stench of rotten eggs.

Early explorers called mudpots "most repulsive and terrifying", and the heat and smell would normally be enough to keep people away even without the many warning signs erected by park staff, but some visitors still insist on wandering off the boardwalks and getting perilously close to the stinking, steaming mud.

Park visitor Milly R spotted one such incident during a recent trip, and shared a recording online as an example of what not to do. The clip, which you can watch below, shows a woman standing right next to a steaming mudpot, getting a face full of hydrogen sulfide gas.

At low levels, this can cause irritation of the eyes, nose, and throat. Higher levels can cause headaches, dizziness, nausea, vomiting, and difficulty breathing. High levels can lead to unconsciousness, coma, and even death.

That's not the only risk, either. The ground around geothermal features like springs, pools and mudpots can be extremely fragile, and the groundwater just underneath is hot enough to cause severe burns within seconds.

The NPS warns that "hot springs have injured or killed more people in Yellowstone than any other natural feature" in Yellowstone. Visitors should always stick to established boardwalks and trails, and never touch thermal features or runoff, or throw objects into pools.

"Toxic gases may accumulate to dangerous levels in some hydrothermal areas," the NPS adds. "If you begin to feel sick while exploring one of our geyser basins, leave the area immediately."

CATEGORIES
Cat Ellis
Former editor

Cat is Homes Editor at TechRadar and former editor of Advnture. She's been a journalist for 15 years, and cut her teeth on magazines before moving online. She helps readers choose the right tech for their home, get the best deals, and do more with their new devices.

Read more
Man reading sign at Morning Glory Pool, Yellowstone National Park
Earthquake rattles Yellowstone National Park's oldest, hottest area
Lava flows in the sea in Hawaii
"National Parks are not playgrounds" – caution urged after toddler makes a break for it during volcanic eruption
yellowstone national park
Yellowstone super-volcano unlikely to erupt anytime soon, say scientists
Yellowstone fires
Yellowstone National Park at an increased risk of wildfires due to standing dead trees, warn researchers
Mount Etna
Hikers flocking to see eruption of Mount Etna cause chaos, blocking emergency services and putting themselves in danger
Sunrise over Yavapai Point, Grand Canyon
Popular Grand Canyon trails reopen after a poisonous gas leak at a source for drinking water forced closures
Latest in Hiking
66°North jacket
Explorer Chris Burkard teams up with 66°North to launch outdoor gear inspired by his photography
Pali Lookout
Hiker arrested after allegedly attempting to murder his wife by pushing her off a Hawaii trail
Columbia Newton Ridge hiking boots deals image
No, it's not a typo – you can pick up these bestselling Columbia hiking boots for as little as $38 right now in Amazon's Big Spring Sale
Komoot App
Big changes may be coming for Komoot users as the navigation app is taken over by firm with a history of slashing jobs
Poster for the film Designed by Disaster showing Campanile Basso in the Italian Dolomites
"Designed by disaster" – new film chronicles a climber's path from near-death to a trailblazing solution for climbing and hiking falls
A woman holding the Katadyn BeFree AC 1.0 L Water Filter Bottle
This innovative soft bottle uses activated carbon to source clean drinking water in the wild, and might have us ditching our Lifestraw
Latest in News
66°North jacket
Explorer Chris Burkard teams up with 66°North to launch outdoor gear inspired by his photography
Pali Lookout
Hiker arrested after allegedly attempting to murder his wife by pushing her off a Hawaii trail
Snow avalanches down the northeast fork of the Kahiltna Glacier
Pro snowboarder, The North Face manager among those killed by giant BC avalanche
Columbia Newton Ridge hiking boots deals image
No, it's not a typo – you can pick up these bestselling Columbia hiking boots for as little as $38 right now in Amazon's Big Spring Sale
Merrell Trail Glove 7
Connect with nature and save 25% off these unique barefoot trail running shoes from Merrell
Yeti Tundra deals image
The spacious Yeti Tundra Haul wheeled cooler is a "powerhouse" that keeps drinks chilled and bears at bay – it's a rare $85 off