A 65-year-old man is recovering from serious injuries after a bison tossed him into the air at Yellowstone National Park. According to ABC News, the unidentified man was walking with his grandson in a campground when the agitated animal charged at him.

Mike MacLeod, a local park photographer, witnessed the attack and captured it on video. He told ABC News that he didn’t believe the bison would chase those two people because they were farther away from the animal than other people.

The video shows the bison resting on the grass. As the grandfather and his grandson stop to take a photo, the animal stands up and begins to move toward the pair as they attempt to flee. The bison then chases the grandfather through and around the trees and eventually catches up to him, tossing him 8 feet into the air.

MacLeod tried to distract the bison by yelling and jumping up and down, and then he put down his camera and rushed to the injured man’s assistance. "He was in a lot of pain and he was trying to not move his leg, but his immediate concern was for his grandson," Macleod said, adding that the grandson was shaken, but OK.

MacLeod said he’s been in touch with the grandfather’s family, who said the man had surgery for several broken leg bones but is expected to recover.

Yellowstone Park officials say bison have injured more park goers than any other animal. "They are unpredictable, can run three times faster than humans and will defend their space when threatened," a statement said. "Wild animals can be aggressive when people do not respect their space. Visitors are responsible for staying at least 25 yards away from all large animals, including bison, elk, bighorn sheep, deer, moose, and coyotes."