Travis Walton was part of a logging crew. He was abducted by a UFO / UAP craft. He and the other 6 members of the logging crew testified to this. The crew was present when he was taken. Travis was missing for nearly a week.
As far as abduction cases go, this is probably one of the best ones. There were 7 total people present who witnessed the event. One was taken and the others were not. As Travis says in this interview, if you had 7 people who were eye witnesses to a crime and they testified, that would be an open and shut case. All of those who witnessed this have stuck to their stories for 50 years now.