By Steve Quinn
JUNEAU, Alaska, March 5 (Reuters) - A 38-year-old veteran Alaska musher competing to win the Iditarod Trail Sled Dog Race became the first on Wednesday to reach the halfway point on a course whose early sections have been described as among the most grueling in years.
In the fourth day of the nearly 1,000-mile (1,600-km) race, Aaron Burmeister, who placed 11th last year, led the pack through the trail's mining district where the town of Cripple is considered the official midpoint.
Former champions Jeff King and John Baker trailed but were not far behind in the race, which commemorates a 1925 rescue mission that carried diphtheria serum by sled-dog relay to the coastal community of Nome, also Burmeister's hometown.
Dozens of mushers and their dogs had set off on Sunday in the town of Willow, near Anchorage, on a journey northwest across the Alaskan tundra that the fastest will complete in a little over nine days.
While most competitors are from Alaska, the race has drawn entrants from as far away as Norway, New Zealand, Australia, Canada, Sweden and Jamaica. This year's winner will receive $50,400 and a new truck, while other top finishers will take home cash prizes from a race purse that exceeds $650,000.
Even if Burmeister, who has run 14 Iditarod races and twice placed among the top 10 finishers, does not prevail at the end, he will still pocket $3,000 worth of gold nuggets for being the first to arrive in Cripple.
Still, many mushers including Burmeister had not completed a mandatory 24-hour rest coming into Cripple, so the leaderboard will be in a constant state of flux until all contenders have completed the stop.
MANDATORY REST PERIOD
This is why one race analyst said he considered former champion Martin Buser, who completed his rest while nursing a sore ankle, as the leader even as he trailed more than 20 other mushers on Wednesday morning. He later guided his team into the top 10 by late afternoon.
"Martin is the true leader of the race once he catches up to the teams who have yet to take their 24-hour layover," said retired Iditarod racer Sebastian Schnuelle, who has been posting reports on the Iditarod website.
He added that Robert Sorlie, a Norwegian former champion returning after a six-year break, will also have a "super powerful team" once his 24-hour layover in the town of Takotna is complete.
Several pre-race favorites chose Takotna for their rest, including defending champion Mitch Seavey and his son Dallas. Two-time runner-up Aliy Zirkle, who held the lead before pulling into Takotna on Tuesday night, also declared an intent to rest there. Should Zirkle win, she would be the first female champion in over a decade.
Of the 69 racers who set off on the race, 12 have withdrawn, succumbing to portions of a trail Schnuelle said "has not been this difficult in decades." Dropouts include race veteran Scott Janssen, known as the mushing mortician, who broke his leg, according to his Facebook page.
Reports of broken bones, sprained joints and severe bruises accompanied stories of trail sections that featured exposed rocks and tree stumps that revealed because of a snow-short winter. (Editing by Cynthia Johnston and Lisa Shumaker)