By Steve Quinn
March 2 (Reuters) - Iditarod competitors from all over the world will set off from a frozen lake on Sunday for the true start of Alaska's famed sled-dog race, a day after the 69 mushers and their canine teams made a ceremonial jaunt through Anchorage.
The nearly 1,000-mile (1,600-km) Iditarod Trail Sled Dog Race commemorates a 1925 rescue mission that carried diphtheria serum by sled-dog relay to the coastal community of Nome, which remains the final destination in this 42nd edition of the event.
The official restart will be held on an ice-covered lake in Willow, a small community about 50 miles (80 km) north of Anchorage, which on Saturday hosted the race's untimed, ceremonial start.
Fans reaching out to high-five competitors lined the streets of Anchorage. The next stage of the competition will be lonelier, as competitors brave darkness, steep climbs and temperatures well below freezing.
"For us, this is a lifestyle," said reigning champion Mitch Seavey, 54. "The Iditarod is the final exam. It validates what we work for year-round."
After Willow, the next checkpoint is 42 miles (68 km) away at the tiny settlement of Yentna Station.
A total of 69 mushers, most of them from Alaska, will travel in stages of between 18 miles (29 km) and 85 miles (137 km) as they guide teams of dogs from Willow northwest through 21 other Alaska villages on the road to Nome.
Competitors have come from Norway, New Zealand, Australia, Canada, Sweden and even Jamaica.
"We do have a larger contingent this year from Norway that we think is going to make for some even stiffer competition," said Stan Hooley, the race's executive director. "From a race fan's standpoint, somebody who is really dialed into the competition, I expect it to be a thriller."
An Iditarod race usually last slightly longer than nine days. This year, the winner will receive $50,400 and a new truck, while other top finishers will take home cash prizes from the race purse, which totals over $650,000.
This will be Mitch Seavey's 20th race, and his second time defending his title. Seavey is among six mushers in this year's competition who have won an Iditarod, but a quarter of the participants are rookies.
Seavey said he expects to fend off a challenge from Norwegian musher Robert Sorlie, 56, who has competed in four Iditarods and won twice.
Missing from this year's lineup is four-time champion Lance Mackey, who is sitting out for health reasons for the first time since 2003. Mackey won four straight races from 2007-2010 while fighting cancer. (Reporting by Steve Quinn in Seattle; Editing by Alex Dobuzinskis and Lisa Shumaker)