As of midweek, Park Service investigators declined to say whether they had found signs of damage to the arch. But a photographer dispatched by Outside—who used a telephoto lens to take pictures of the area directly above Potter's route—identified three distinct grooves worn by rope into the sandstone. (Each appears to be roughly a fourth of an inch deep and several inches long and is invisible to the naked eye from ground level.) In addition, Jason Keith, a Moab-based policy director with the Access Fund, a climber-advocacy group, says that, out of curiosity, he examined the arch in mid-May with a spotting scope and saw as many as five additional grooves that are visible on a different spot near the summit.

Arches officials have decided Potter's climb was not illegal, due to vaguely worded regulations that have since been made crystal clear to prohibit any more arch climbs. But according to Karen McKinlay-Jones, the park's acting chief ranger, officials are looking for damage to Delicate Arch with "a priority over everything except life and limb." (She wouldn't comment further on how they're investigating.) The park's superintendent, Laura Joss, adds, "If there is damage to Delicate Arch, that is of grave concern to us."

Rick Ridgeway, vice president of communications at Patagonia—one of Potter's main sponsors—says the company is "adamantly opposed" to acts that damage any natural setting and that it would likely reevaluate its relationship with Potter, one of Patagonia's top-ten paid athletes, if it turns out his climb damaged the formation. In any event, Ridgeway says it's now incumbent upon Potter to come clean about exactly what he did. "To say that he was just there to commune with nature is half the story," he says. "It's time to be frank."

Potter insists the climb left no trace. "The marks up there are not mine, absolutely, and I know for a fact that other people have been up there," he says. "So it's crystal clear: When we were doing this arch climb it was in all of our minds that the super priority was to be careful of the rock: Don't harm the rock, move slowly, don't do anything at all if you are going to harm the rock. I'm so in tune with rocks and nature. On any rock around the world, if I hurt the rock, I feel like I'm hurting myself."

Malcolm Daly, the 51-year-old founder of climbing-gear company Trango and a friend of Potter's, says any potential damage to the arch is a "tragedy." But another issue for him, he says, is one of profound disappointment, and it cuts deeper than a rope groove. After first supporting Potter and getting roasted for it on climbing Web sites like Mountain Project (www.mountainproject.com), Daly has now become a critic.

"There are many people who think Dean just walked up there and climbed it," Daly says. "I wanted to think that, because I have all this respect for him and this spiritual context under which he says he climbs. And I think other people want to believe that. That's why I feel so hurt. He did rehearse it. It was for a photo shoot. It was a communal effort by a group of people, and there is damage to the arch. It takes all the polish off the diamond."