Two hikers were attacked by one or more bears at Yellowstone National Park, officials said on Tuesday, marking the first time this year a bear has injured people at the popular tourist attraction.

The National Park Service said emergency personnel responded to the attack, which occurred Monday afternoon on the Mystic Falls Trail near the iconic Old Faithful geyser. Park officials said the incident is under investigation and did not reveal the extent of the hikers’ injuries.

Craig Lerman, a tourist from Maryland, told Cowboy State Daily that he spotted one of two injured hikers after hearing a voice call out: “Help me.”

“I was hiking up Mystic Falls Trail when I saw bear prints in the mud,” Lerman told the outlet Tuesday. “I kept walking a little further and saw a bloody hat with a watch torn off.”

Lerman told Cowboy State Daily the injured man was “tore up pretty bad” with cuts all over his body. He said he called 911, followed instructions from the dispatcher and waited with the hiker.

“He kept talking to me the entire time,” Lerman told the outlet. “I ended up giving him my T-shirt (because) he said he was cold and wet, so I just laid it over him and reassured him help was on the way.”

The most recent bear attack in the park was in September when officials said a 29-year-old hiker was seriously injured in a “surprise encounter” on the Turbid Lake Trail.

The last human fatality caused by a bear inside Yellowstone National Park occurred in 2015, but a grizzly killed a woman just west of the park in 2023.

After Monday’s attack, at least five trails and multiple campsites at the park were closed. The park reminded visitors to stay at least 100 yards away from bears, carry bear spray and look for possible signs of the animals.

“See the bear before you surprise it,” the park said. “Watch for fresh tracks, scat, and feeding sites.”

In March, scientists spotted the first grizzly bear of 2026 at Yellowstone, marking the beginning of the end of hibernation season for the animals.

There are more than 1,000 grizzlies living across what’s called the “greater Yellowstone ecosystem,” an area covering portions of Montana, Idaho and Wyoming outside of the immediate park boundaries.

Grizzly bears are currently listed as threatened under the Endangered Species Act, after they were brought back from the brink of extinction in the contiguous United States over the last five decades. Yellowstone officials have estimated the grizzly bear population in the region had dropped to just 136 in 1975. But, thanks to conservation efforts, scientists now consider the population to be doing well, occupying more than 27,000 square miles and expanding their habitats.