Foot (and shoe) found floating in a Yellowstone park hot spring

An investigation is under way after a Yellowstone employee spotted part of a foot, in a shoe, floating in a hot spring in the national park.

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The discovery was made on Tuesday at Abyss Pool, in the southern part of Yellowstone, and led to the temporary closure of the West Thumb Geyser Basin and its parking lot.

Park officials are now investigating the discovery and said on Friday that they believe it is linked to the death of a person last month. Foul play is not suspected in the 31 July death, park officials said in a statement. The statement did not disclose further details about the death or identify the person who died.

The park did not have any additional information about what happened, said park spokesperson Morgan Warthin on Thursday.

Abyss Pool, located west of the West Thumb of Yellowstone Lake, is 53ft (16 meters) deep and the temperature is about 140F (60C), park officials said. It is on the south side of the southern loop through the park.

In such hot springs, superheated water cools as it reaches the surface, sinks and is replaced by hotter water from below. The circulation prevents the water from reaching the temperature needed to create a geyser, according to the park’s website.

Hot springs are among Yellowstone’s most famous attractions but can also be dangerous, even deadly. “Hot springs have injured or killed more people in Yellowstone than any other natural feature,” according to the website. At least 22 people are known to have died from hot spring-related injuries in and around the park since 1890, park officials have said.

Visitors are warned to stay on the boardwalks and trails in thermal areas, where some of the pools and springs have a thin, breakable crust covering the scalding and sometimes acidic water.

The most recent death occurred in 2016, when an Oregon man “dissolved” after he slipped and fell into a boiling, acidic spring. No significant human remains were recovered.

The park has seen soaring popularity with 4 million annual visitors in recent years. Historic flooding forced the closure of the entire park for part of June. The park’s northern and north-eastern entrances are still closed to vehicles.