Rick Swenson, the winningest musher in Iditarod history, won't make the trip to Nome this year. Swenson pulled out of the Iditarod Trail Sled Dog Race on Thursday, race officials said.

Swenson, the only five-time champion in the history of the race, withdrew "citing personal reasons," communications director Erin McLarnon said in an email.

The 62-year-old Two Rivers musher has finished the race 35 times, including 24 top 10 finishes. Swenson placed 20^th in the 2011 Iditarod despite breaking his collarbone in a crash at the Happy River Steps just two days into the race.

"I've known Rick for a long time, raced with him, and it's an extreme disappointment," Iditarod race marshal Mark Nordman told the Fairbanks Daily News-Miner. "He's the man of the trail and has knowledge to pass on to all the mushers."