Two men that were videoed chasing bison on motorcycles pleaded not guilty in court last Monday.
According to For The Win, a park spokesman said brothers Dallin McAllister, 25, and Tyler McAllister, 36, were cited for approaching and disturbing wildlife, and operating motor vehicles in a prohibited area.
Their alleged crimes were caught on video and posted online.
While authorities at Yellowstone National Park declined to confirm the video was part of the investigation, a spokesman sad off the record that the video was related.
The brother have another court date scheduled for sometime this fall where they will attempt to defend themselves against this video evidence.
Tourists have a long history of harassing bison. An incident during a Sturgis motorcycle ride let a woman pantless when a bison she approached charged and got its horn caught in her belt.