HELENA, Mont. (AP) — A part of a human foot found in a shoe floating in a hot spring in the southern part of Yellowstone National Park earlier this week is believed to be linked to a July 31 death, park officials said Friday.

While the investigation continues, foul play is not suspected.

The shoe was recovered from Abyss Pool on Tuesday, park officials reported. News of that discovery led a man from Maryland to contact the National Park Service to report that he and his family had spotted a shoe, floating sole up, in the hot spring on the morning of Aug. 11.

Chris Quinn of Pasadena, Maryland, said he sent a photo of the shoe to the park service.

While the park service did not confirm it was the same type of shoe found Tuesday, Quinn said he would be surprised if it’s not related to the same incident.

Abyss Pool, located west of the West Thumb of Yellowstone Lake, is 53 feet (16 meters) deep and the temperature is about 140 degrees Fahrenheit (60 Celsius), park officials said.

At least 22 people are known to have died from hot spring-related injuries in and around the 3,471-square-mile (9,000 square kilometer) national park since 1890, park officials said.

The most recent occurred in June 2016 when Colin Nathaniel Scott, 23, of Portland, Oregon, left a boardwalk in the Norris Geyser Basin, slipped on some gravel and into a boiling, acidic spring. No significant human remains were left to recover.

The nation’s first national park has drawn more than 4 million visitors over the past several years, with the exception of 2020, when it was briefly closed due to the pandemic. The park had closures in June due to historic flooding. It’s northern entrance at Gardiner and its northwestern entrance near Cooke City remain closed to vehicles.