Former Iditarod champion Joe Runyan was the first musher to leave this namesake ghost town halfway through the Iditarod Trail Sled Dog Race Friday, taking the lead in the race's seventh day.

Runyan, who won the Iditarod in 1989 and finished second to four-time winner Susan Butcher last year, set out from Iditarod on the 65-mile leg to Shageluk, the next checkpoint, at 10:28 a.m.Racers mush from Anchorage to Nome, commemorating a historic 1925 relay of diphtheria serum to ailing Nome residents during an epidemic.

Meanwhile, musher John Ace was forced to drop out of the race after he fell and injured his leg.

Runyan had been the seventh musher to pull into Iditarod, at 4:13 a.m. Butcher arrived first and waited for DeeDee Jonrowe, with whom she said she had broken much of the trail from Ophir. They checked in together at 1:38 a.m. and split the $3,000 halfway prize.

It took Butcher and Jonrowe more than 24 hours to travel from the Ophir checkpoint to Iditarod, a 90-mile run across rolling, unpopulated terrain that usually takes about 12 hours to cross.