Mckenna Bass, 37, also of Idaho Falls, was arrested along with Yoder for allegedly driving under the influence, disturbing wildlife and failing to yield to an emergency light activation.
According to court documents, Yoder and Bass pleaded not guilty and were each released on a $3,500 bond. They are banned from Yellowstone while their cases are pending. Yoder has a status hearing scheduled for May 23. Bass’s is scheduled for July 2.
Violations at national parks related to wildlife, plants and natural or cultural features carry a maximum penalty of $5,000 and up to six months in prison.
Tourists harassing wildlife has long been a problem at national parks, with social media making incidents more visible. The National Park Service said this was the first time this year that a bison had injured a visitor at Yellowstone.
Jared Beaver, an assistant professor and wildlife management specialist at Montana State University, said wildlife harassment has started early this year.
“June and July is usually when it gets cranked up,” he said.
Of all the wildlife in Yellowstone, he said bison cause the great number of injuries to visitors. Last year, the park reported its first incident in July, when a bison gored a woman from Arizona. She was flown by helicopter to a medical center.
Beaver said the bigheaded bison, which can weigh up to 2,000 pounds, can turn aggressive when they sense a threat in their personal space. He said almost all bison attacks have occurred when the victim was within 10 to 15 feet of the animal. The national park requires visitors to stay at least 75 feet away.
Bison exhibit clear signs of agitation. Beaver said they will snort, toss their head and may fake a charge. A flat tail is a relaxed bison. An extended tail aligned with its back means that it is on alert. When the tail stands straight up and resembles a question mark, an attack could be imminent.
“Be aware of your surroundings and make sure that you’re responding to that animal’s movement and giving it plenty of room,” he said. “All it takes is one wrong movement that might upset that animal.”