It is said that Joseph Nielson discovered this amazing sink hole in 1927. He was heading back to his camp at night when he strayed into the area. His horse stopped and absolutely refused to go another step. He got off the horse and started walking, when suddenly he was hanging on to the reins of his horse with nothing below his feet. Fortunately, Nielson was able to coax his horse to back up while he was holding the reins and get out of the mysterious hole he found himself in. The next day, Nielson went back to see in the daylight what had tried to swallow him. As he neared the sinkhole, once again his horse refused to move close.