An 83-year-old Greenville woman was seriously injured after being gored by a bison in Yellowstone national Park, the National Park Service said.

The woman, who was not identified, was lifted about a foot off the ground. She was taken by park emergency workers to the Lake Medical Clinic and then flown by helicopter to Eastern Idaho Regional Medical Center in Idaho Falls, Idaho.

The animal was defending its space, the park service said, adding a warning for people to stay at least 25 feet away from them. Bison have injured more people than any other animal in Yellowstone, park officials said.

The park service said bison are not aggressive but will defend their space and can run three times faster than a person.

“They are unpredictable,” the Park Service said.

The incident took place June 1 near the Storm Point Trail, a relatively easy, 2.3-mile loop trail beside Indian Pond, through a forest to the northern shore of Yellowstone Lake. The trail is often closed in the spring due to bear activity, the National Park Service said.