Iron County authorities are mystified by an apparent attack on two Wyoming tourists who reported they were bashed on the heads with a large rock as they slept in a campground.

Don J. Burgess, 33, and Jamie Frank Walton, 26, of Dubois, Wyo., said they were passing through the area and had stopped to spend Wednesday night in the U.S. Forest Service campground 12 miles east of here.They said they both were sleeping in the otherwise empty campground when someone struck Burgess over the left eye and Walton on the forehead, said Deputy Richard Payton.

Walton took Burgess to Valley View Medical Center in Cedar City, where both were treated. Burgess was transferred to Dixie Medical Center in St. George and later released.

Detective John R. Williams said Friday that neither of the men could describe the assailant and no suspects had been identified.

"They didn't see or hear a vehicle, they don't know how many people were involved, nobody said anything," he said. "It's probably the goofiest thing I've ever heard off."

The men did recall that two men in a compact station wagon drove up to their campsite at 9:30 p.m. the night before, asked for someone, then drove away.

"I don't have a clue. I went up there again yesterday and looked again," Williams said. "I can't find where any struggle took place or anything. It's kind of a baffling thing to me."