And so it begins...

A bison wanders along a traffic jam in Yellowstone National Park

An Arizona man and a Utah man each pleaded not guilty Monday to charges that accuse them of riding motorcycles off-road in Yellowstone National Park and harassing bison.

Dallin McAllister, 25, of Utah, and Tyler McAllister, 36, of Arizona, are each charged with operating a motor vehicle in prohibited areas and feeding, touching, teasing, frightening or intentional disturbing wildlife. Both appeared in federal court in Yellowstone before Judge Kelly Rankin.

On Friday around 5:30 p.m., people rode motorcycles off-rode near the Fountain Flats Drive, said Ashton Hooker, spokesperson for the park.

In a Facebook group titled “Yellowstone National Park: Invasion of The Idiots!” a user posted a video showing two motorcyclists riding off road within feet of several bison, including some calves. A woman on the video could be heard yelling at the motorcyclists “get out of the field.”

The video shows the motorcyclists ride away from the bison as a herd chases them back onto the road.

Hooker said there would be a court hearing sometime this fall, though that is not scheduled.