Transcript for Mysterious structure disappears from Utah desert
We'll get the latest on the mysterious monolith that appeared and disappeared in the unite desert. Will reeves has the details. Reporter: A bunch of people only half jokingly decided it had to be aliens, which in any other year would have been the story of the year. Now, poof, it's gone. This morning another twist in the Utah desert, this silver monolith vanishing ten days after it was discovered. E showed up and there was nothing there. We were like what is happening? It was scary. I was nervous. Reporter: Utah officials happened upon this 10 to 12-foot metal beam in a remote canyon. It's the weirdest experience I've had in the desert. Reporter: Theories aboundabounded. Was it art, aliens? Then as confoundingly as it appeared, it vanished, almost without a trace. Hikers journeying out to see the object finding rocks marking where it was. Kind of a hard thing to investigate. We don't know where it came from, when it came from or where it went. Reporter: Federal officials announced the monolith's disappearance blaming an unknown party. It's surprising it lasted as long as it did. It's even more surprising it disappeared in the middle of the night. Reporter: Officials did not disclose its location. Some curious folks made the trek to see the piece. It was nice to haven minutes of peace with what I would call a landmark that not many people had been to. That was pretty cool. Reporter: The gallery that represents the estate of artist John mccrack even says it looked like a bona fide piece from him. The mystery continues. Reporter: Do you think it would have been the story of the year if we saw aliens bring it down and take it back up? Come on.
This transcript has been automatically generated and may not be 100% accurate.