As the Iditarod prepares to shift into reverse, mushers dread what’s ahead Wait 1 second to continue. OPHIR — Iditarod Trail Sled Dog Race mushers are contending with an unprecedented situation this year, one that is stirring anxiety as racers ruminated during their 24-hour mandatory rests on Wednesday. For the first time, the Iditarod is following an out-and-back route. That means competitors now have a clear idea what’s in store when they go back over daunting sections of trail. “On a normal year, you just go and you hit a bad spot, and you’re through it and you just forget about it,” said race veteran Paige Drobny of Cantwell, wearing a billowy white jacket as she inspected the inside of a dog’s nostril.