Weeks before an agitated bison charged a 9-year-old in Yellowstone National Park, a jackass visitor was filmed petting one of the massive beasts, disturbing video shows.

The man — seen in footage reaching over a fence to pet the animal on the head — was lambasted by park officials Wednesday for his “incredible lack of judgment and common sense.”

The Cheyenne, Wyo., park said Wednesday they’re investigating the YouTube video posted July 8 to determine who the man was.

“Not only did he put himself and others at risk, he violated regulations designed to keep these animals wild,” park superintendent Cam Sholly said in a statement. “We expect better from our visitors.”

Park officials have urged visitors to steer clear of all large animals, including bison, after the incident last month involving the 9-year-old Florida girl.

On July 22, a raging bison tossed the girl several feet into the air after a group of tourists came within feet of the animal.

The child was tended to by park emergency workers before she was brought to Old Faithful Clinic, according to the National Park service.

With Post Wires