The man, whose real name has not been reported, posted a video to YouTube of what he says he believes may be Bigfoot, KSTU-TV, Salt Lake City, reported Saturday.
The man said he and a friend were hiking near Squaw Peak and Little Rock Canyon Overlook when they spotted what they believed to be a bear.
But when "the monster stood up and looked right at us," they fled.
"We had actually been standing there for awhile. We had thought it was a bear up to that point but when it stood up and looked at us it was just massive animal," said the video's uploader.
"We don't know what it was. I mean none of us really believe in Bigfoot but we've talked about it over and over again since then. It happened on Monday and all of us are positive that thing wasn't a bear," the uploader said.