First, about the weather: The race will run the southern route, which is 13 miles longer than the northern route, for the first time since 2013. Race officials have gone away from the every-other-year route choice in favor of the northern route for the past four years because of poor trail conditions and, surprisingly, not enough snowfall.

The ceremonial start will kick off at 10 a.m. local time on Saturday in Anchorage, with a forecast of temperatures just below freezing and a few inches of snow. The city already has about two feet of snow on the ground, a much higher total than last year, when organizers had to bring in snow from elsewhere in the state.

The real race start is 2 p.m. local time on Sunday in Willow. Looking to repeat will be three-time champion Mitch Seavey (left), who last year set a course record of 8 days, 3 hours, 40 minutes, 13 seconds.

Not racing this year will be last year's second-place finisher and himself a four-time winner, Dallas Seavey, Mitch's son. The younger Seavey is in Norway, racing in the Finnmarkslopet, another sled dog race.

Dallas Seavey was the subject of a doping investigation last year after four of his dogs tested positive for tramadol, a banned painkiller. Seavey denied giving the drug to his dogs, and race organizers have no proof that he did. He was not punished. A change to the rules now means that mushers whose dogs fail a drug test can be held liable unless they can compete that someone else did the doping.

The younger Seavey has also been a target for protests by the People for the Ethical Treatment of Animals (PETA), an organization that has long labeled the race as cruel to the dogs that compete. PETA last year claimed that Dallas Seavey was mistreating his dogs. In the 2017 Iditarod, five dogs (none of them Dallas Seavey's) died.

A handful of PETA protesters will be at the race start and at the finish line, calling attention to their allegations. Similar allegations were at the heart of a 2016 Canadian documentary on the Iditarod.

The race's board is also under threat amid allegations of mismanagement, in the wake of the departure of a high-profile longtime sponsor.