An investigation is under way after a Yellowstone employee noticed a part of a foot in a shoe floating in a hot spring in the national park.
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. The area has been reopened since.
Park officials are now investigating the discovery but did not have any additional information about what happened, said Morgan Warthin, park spokeswoman for the park.
Abyss Pool, located west of the West Thumb of Yellowstone Lake, is 53 ft 16 meters deep and the temperature is about 140 F 60 C park officials said. It is located on the south side of the southern loop through the park.
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 some of Yellowstone's most famous attractions but can also be dangerous, even deadly. Hot springs have killed more people in Yellowstone than any other natural feature, according to the park.
In 2016, an Oregon man was killed and his body dissolved after he fell into a boiling, acidic spring.