From this story in the Arizona Daily Sun_ (via Outdoor Pressroom):
_A North Carolina man received five years of probation, a $10,000 fine and must serve 100 hours of community service after pleading guilty to damaging a petroglyph on the Colorado River. According to information from the U.S. Attorney's Office, Trenton Austin Ganey, 29, pleaded guilty in December 2010 to damaging an archaeological resource. Ganey had been on a fishing trip on the river below Glen Canyon Dam in June 2010. While his trip was stopped on a beach, he hiked to the Descending Sheep Panel and scratched his name into the panel. Park Rangers discovered the damage a short time after Ganey's party left and caught up with him. He admitted to committing the offense and was remorseful for his actions.