Bison dies after falling into hot spring at Yellowstone National Park in front of visitors: “A front row to nature”

A bison died after it appeared to stumble into a hot spring at Yellowstone National Park last week while visitors looked on.

The incident occurred during the early morning of June 21 at Grand Prismatic Spring near Old Faithful as tourists were enjoying a close-up view of the famous and popular hot spring, according to witnesses and a spokesperson for Yellowstone.

“There were two bison (standing) there,” said Louise Howard, who was visiting Yellowstone from Colorado for the first time. “I thought it was a great photo opportunity.”

She told CBS News on Friday that one of the bison started walking toward the spring and appeared to step into a shallow part before quickly jumping out. She said that in a manner of about 30 seconds, the bison started walking but stumbled at the edge of the spring and fell in.

“As hard as it tried, it couldn’t get out,” said Howard, who shared photos on social media.

Rare, but not unheard of

Michael Poland, scientist-in-charge at the Yellowstone Volcano Observatory and a geologist with the U.S. Geological Survey, told CBS News on Friday it is not unprecedented that animals fall into hot springs. He said scientists have found skeletons at hot springs around the park, many of which are in the backcountry, not visited by tourists.

“There is one pool (in the Lower Geyser Basin) called Skeleton Pool,” he said. “What made this a little bit different is that it happened in summer, during the day, at one of the most popular tourist areas in the whole park.”

Poland said animals usually fall into the hot springs because they are walking too close to the edge and it collapses.

“There are thin crusts that form on the edges of these and so it’s difficult to tell if there is boiling water directly beneath you,” he said. “What exactly happened in this case, it’s impossible to say.”

“There are animals that walk through that area all the time. When you walk on the boardwalk, you can look down into the water, and you can see all kinds of animal footprints – bison, elk, coyotes, so forth,” Poland added.

Nothing could have been done

Poland said the bison died fairly quickly after falling into Grand Prismatic, where temperatures reach about 192 degrees Fahrenheit. The boiling point at Yellowstone is about 200 degrees Fahrenheit because of its high altitude.

He said people can tell how hot the springs are based on the color of the bacteria near the edges.

“All those colorful edges on Grand Prismatic are different bacteria that live at different temperatures,” he said. “The red colors are bacteria that like warm water but not scalding and then as you go in from red to yellow to green, it gets to be hotter and hotter. And then the blue water, there is no bacteria there and that’s the hottest water, and in many cases, that is really close to boiling.”

Poland dispelled rumors that the water in Yellowstone hot springs is highly acidic, saying that most springs in the park are actually neutral – just really hot.

“What’s dangerous is the fact that they are very close to boiling,” he said. “Anyone who’s poached a chicken knows what that will do to tissue.”

A cautionary tale for visitors

Millions of tourists visit Yellowstone National Park each year – particularly in the busy summer season.

This incident – and the two events of bison goring tourists this year – are a cautionary tale for visitors who want to enjoy the park and everything it has to offer, Poland said.

He urged people to stay on the boardwalks and follow the rules that Yellowstone’s rangers have laid out for visitors.

Yellowstone National Park is renowned for its diverse and abundant wildlife. Visitors commonly see bison, elk, bears and other animals, including wolves, moose, mountain goats and mountain lions.

Anyone walking away from the boardwalks risks injury from the hot springs or wildlife but also risks damaging the landscape.

“The trails are there for a reason. We’re in their environment,” he said of the animals. “It’s a wild place. The landscape is wild too.”

Howard said that despite the tragic incident, the three days she spent at Yellowstone were some of the best of her life.

“You never get such a front row seat to nature,” she said, adding: “I think some people see Yellowstone as a zoo because of how they interact with the animals but it’s not. Those animals are wild and they are doing their thing. We are guests in their area.”