A bull bison tossed a nine-year-old girl into the air when the animal charged a group of about 50 tourists, Yellowstone National Park officials said.
They said the bison charged the group on Monday after some of the tourists approached to within five to 10 feet of the animal for at least 20 minutes.
The girl, from Florida, was taken to Old Faithful Lodge by her family for treatment by emergency personnel. She was later taken to a clinic and discharged.
Park officials did not disclose the extent of any injuries.
The incident happened near Observation Point Trail, in the area of Old Faithful Geyser.
Injuries of tourists by bison and other wildlife occur regularly in Yellowstone, which gets about four million visitors annually.
- Press Association