After being closed for nearly two months, Yellowstone National Park started its phased reopening on Monday, May 18. Just two days later, on Wednesday, visitors were already acting up.

A woman who got too close to a bison was knocked to the ground and injured by the animal in the Old Faithful Upper Geyser Basin. The visitor was immediately assessed by the park’s emergency medical providers and refused to be transported to a medical facility.

Park officials said it was the first bison attack on a visitor this year.

It goes without saying that visitors to the park shouldn’t approach wildlife. Last summer, the park published a humorous diagram to outline the proper way to interact with the bison.

In a news release, officials reminded the public of the proper behavior to exhibit when around the park’s wild animals. “When an animal is near a trail, boardwalk, parking lot, or in a developed area, give it space. Stay 25 yards (23 m) away from all large animals — bison, elk, bighorn sheep, deer, moose, and coyotes and at least 100 yards (91 m) away from bears and wolves. If need be, turn around and go the other way to avoid interacting with a wild animal in close proximity.”