YELLOWSTONE NATIONAL PARK, Wyo. — A 12-year-old boy is in the hospital after a bison he was posing near flipped him in the air at Yellowstone National Park.

The Pennsylvania boy's condition was not available after the attack Thursday.

Park officials say the boy was posing with family members within a couple of feet of the mature bull bison.

Park rules require visitors to stay at least 25 yards from bison.