Strange things are happening here
IT'S an incredible and beautiful natural attraction in America that millions of tourists flock to every year.
The Yellowstone National Park, which spans three states from Wyoming to Idaho and Montana, is home to fascinating sites such as the Morning Glory Pool, the Grand Prismatic Spring and the Old Faithful geyser.
But lately, odd things have been happening here and the situation is so concerning that officials have issued a warning to tourists.
A spokesman for the park said that in just over a month, four people have been injured by wildlife in Yellowstone, while a nearby geyser has been absolutely going off.
On Thursday, a woman was gored by a bison after she approached within metres of the animal.
Kim Hancock, 59, was with a group of tourists visiting the park when she approached the bull bison while walking along a boardwalk.
"When it crossed the boardwalk, the bison became agitated and charged the crowd, goring Hancock," park officials said in a statement. "The bison immediately left the area."
Ms Hancock was treated at a nearby hospital in Montana and was listed in good condition.
It was the second such attack by a bison this year. On May 1, a 72-year-old woman was also injured by a bison as she walked on a trail in the park and came upon the animal.
She was butted in the thigh, pushed and tossed off a trail.
The other two injuries were caused by elk. Penny Allyson Behr, 53, was attacked in an accidental encounter behind the Mammoth Hot Springs Hotel on Tuesday. She was hit in the head and torso and was taken to hospital for treatment.
It was the same area where employee Charlene Triplett, 51, was attacked by an elk two days prior and flown to hospital.
The attacks have prompted park officials to urge visitors to maintain a safe distance from the animals.
"Animals in Yellowstone are wild and unpredictable, no matter how calm they appear to be," the officials said.
"Give animals space when they're near trails, boardwalks, parking lots, or in developed areas. Always stay at least 91m away from bears and wolves, and at least 23m away from all other animals, including bison and elk. If you can't maintain these distances, turn around and find an alternate route."
It's not just the park's animals that are making headlines. Yellowstone's Steamboat Geyser has just erupted for the eighth time this year, and scientists don't know why.
The tallest active geyser in the world, Steamboat doesn't erupt very often but can eject water 91 metres up.
"It's a spectacular geyser. When it erupts, it generally has very big eruptions," Michael Poland, the US Geological Survey's scientist-in-charge of the Yellowstone Volcano Observator said.
But never fear - experts don't believe the eruptions are a sign the supervolcano beneath Wyoming is waking up.
The series of eruptions started on March 15, and prior to this the last time the geyser was active was in September 2014.
There have been more eruptions in this period than in the past 15 years combined.