Lance Mackey zipped in and zipped out of Kaltag early this afternoon to steal the lead from Jeff King as the race for Nome heated up in the Iditarod Trail Sled Dog Race.

King, the four-time champ from Denali Park who says this is his final competitive Iditarod, was the first to reach Kaltag, arriving behind a team of 13 dogs at 11:42 this morning.

Forty-six minutes later, a dozen dogs delivered Mackey to the checkpoint. Four minutes after that, Hugh Neff of Tok arrived with 13 dogs in harness.

But Mackey didn't tarry at the final checkpoint on the Yukon River. He lingered all of seven minutes before leaving at 12:35 p.m., to begin his 90-mile overland run to Unalakleet, where the trail hits the Norton Sound coast.

Left behind in Kaltag were King, Neff and Mitch Seavey of Sterling, who arrived at 1:04 p.m. with 12 dogs.

Just how long Mackey, the three-time reigning champ from Fairbanks who is aiming for an unprecedented fourth straight victory, intends to travel before resting his dogs is anyone's guess.

"Mackey could be headed for Tripod Cabin or he could be headed even farther," said an Iditarod Insider race report. "Let the gamesmanship begin."

The Tripod Flats cabin, 35 miles down the trail from Kaltag, is one of two BLM-maintained cabins between Kaltag and the coastal village of Unalakleet. Old Woman Cabin is 15 miles beyond Tripod.

The day began for the leaders in Nulato, where minus-35 temperatures settled onto the Yukon River overnight. King led the 61-racer field into the town of 300 at the confluence of the mighty Yukon and Nulato rivers hours before dawn.

Little had changed in the standings from the night before, with King holding a one-hour, 24-minute lead over Mackey. Neff of Tok was another 32 minutes behind Mackey. Farther back were Seavey and Hans Gatt of Whitehorse, both nearly an hour behind Neff.

"I was hoping to be up a little farther," Gatt said in Galena, the checkpoint before Nulato. "You can only do what the dogs can do.

"Right now, I'm just trying to hold the dog team together and not do anything stupid."

Bitterly cold evening temperatures that mushers have endured on the Yukon River have slowed a race that had been moving at or slightly ahead of record pace into Ruby, the first checkpoint on the river.

By the time King left Nulato at sunrise Saturday, he was nearly three hours behind the record pace that four-time champion Martin Buser of Big Lake established in 2002 on the race's northern route.

Instead, he was hewing nearly exactly to the pace of the runner-up that year, Ramy Brooks of Healy. Brooks ended up a solid second, about two hours behind Buser. Brooks' time, 9 days, 49 minutes, was the second-fastest in race history.

The bitter cold and a week of sleepless days were conspiring to force errors -- some big, some simply forgetful.

"I love the mighty Yukon, but today I didn't like it that much because my brain wasn't working very properly at my departure in Ruby and I forgot my beaver mittens," said Sven Haltmann, the Swiss immigrant who now lives in Willow. "It was very, very chilly."

Like most mushers, Haltmann used ski poles to aid his dogs on the river trail, pushing hard for every possible advantage.

"I reached behind my back to get my mittens like I always do," he told the Insider. "Well, I grabbed in the air. 'Oh my God,' I thought, they're still hanging in Ruby inside a house where I hung them up to dry."