Spanning swaths of Montana, Wyoming and Idaho, Yellowstone National Park is home to one of the most famous images to come out of the 63 national parks across the country.

The bright blue, green and orange colors of the geothermal geyser Old Faithful are caused by thermophiles or microscopic organisms that thrive in hot temperatures in spring water rising from deep within the ground.

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As water temperatures within Old Faithful can reach up to 400°F (204°C), visitors to the area are warned to exercise caution and always stay on marked paths to get that psychedelic geyser photo.

‘Broke through a thin crust over scalding water’

On the afternoon of Monday, Sept. 16, a 60-year-old visitor to Yellowstone from Windsor, N.H. suffered second- and third-degree burns to her leg after walking into a thermal area near Mallard Lake Trailhead. She was hiking through it and either accidentally or intentionally wandered off the marked trail; park authorities are not currently providing more details on how the incident occurred.

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“The woman was walking off-trail with her husband and leashed dog in a thermal area when she broke through a thin crust over scalding water and suffered burns to her leg,” writes the National Park Service (NPS). “The woman and her husband went to a park medical clinic where they were evaluated.”

Medical workers at the small medical area in the park evaluated the burns to be severe and the woman and her husband were moved to Eastern Idaho Regional Medical Center by helicopter. This was the first incidence of thermal burn in the park in 2024, although others have occurred in past years.

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‘There is scalding water just below the surface’

The NPS used this incident to remind visitors to respect marked path signs and “exercise extreme caution” around the thermal areas as the water, while looking no different from a regular lake or stream, could actually be at heats high enough to cause major injuries.

“The ground in these areas is fragile and thin, and there is scalding water just below the surface,” the government agency writes further. “Pets are prohibited on boardwalks, hiking trails, in the backcountry and in thermal areas.“

Different injuries to occur at Yellowstone National Park this year include an April incident in which 40-year-old Utah resident Clarence Yoder kicked a herd of bison and ended up getting kicked back (as well as later arrested on charges related to disturbing wildlife and being under the influence of alcohol).

While Yoder’s case is a clear instance of disregarding the most obvious rules of wildlife safety, a separate accident occurred when an 83-year-old woman hiking through Storm Point Trail was gored by a bison who snuck up behind her without notice. As described by the NPS, the visitor from South Carolina was “lifted her about a foot off the ground with his horns.”

“Bison have injured more people in Yellowstone than any other animal,” the NPS wrote in one of several notices it sent out due to a higher-than-normal rate of bad human-bison incidents this year. “Bison are not aggressive animals but will defend their space when threatened. They are unpredictable and can run three times faster than humans.”

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