UPDATE (7-28-19): Park officials confirmed Sunday that a bison struck a 17-year-old Colorado girl Saturday morning in the south unit of the Theodore Roosevelt National Park.

They say she was walking toward the parking lot from the Lower Paddock Creek Trail. There were two male bison who had just finished fighting, one on each side of the trail about 20 feet apart. She walked between them, then one charged her from behind, striking her right leg and sending her six feet in the air.

Officials say this incident is a good reminder to be careful around these wild animals.

"The best thing to do is not get close in the first place, because bison are so fast that you may not be able to react when one starts to charge. They're that quick," said Eileen Andes, Public Information Officer for TRNP.

Andes says bison are enduring their mating season right now, making males more aggressive.

During the season of heightened aggression, it is recommended that visitors stay at least 25 yards away from any bison.

ORIGINAL STORY (7-27-19): A Colorado teen was struck by a bison in the south unit of the Theodore Roosevelt National Park Saturday morning.

Acting Chief Ranger Grant Geis says it happened at around 11:30 a.m. MDT.

Geis says the woman was hiking through a prairie dog town in the Lower Paddock Creek Trail. A herd of bison was also moving through the prairie dog town when one of the bison struck the woman.

She was flown by helicopter to Sanford in Bismarck. Geis says the woman is in stable condition.

The investigation is still ongoing, but Geis says they expect to release more information on Sunday.