Bison injure more people at Yellowstone National Park than any other animal. Photo by Jacob W. Frank/National Park Service

A 12-year-old was injured by a bison in Yellowstone National Park on Friday, marking the second incident this year in which wildlife injured a visitor in the park.

The incident happened near the Mud Volcano area, a popular stop in Yellowstone, located around 20 miles northeast of Old Faithful.

"The visitor sustained injuries, and emergency medical personnel transported them to a nearby hospital," the National Park Service said in a press release. "The incident remains under investigation."

In May, two hikers were injured in a bear attack on the Mystic Falls Trail, prompting temporary closures in part of the park.