RUBY -- Defending Iditarod champion Lance Mackey led the Iditarod Trail Sled Dog Race to the Yukon River today, but four-time champ Jeff King was the musher talking smack when he pulled in just a fews hours behind.As the Denali Park musher led 16 enthusiastic-looking dogs toward a parking spot, he passed Mackey, the Fairbanks musher who already has a victory in the 1,000-mile Yukon Quest International Sled Dog Race to his credit this year.

"Worried yet?" King said.

The question was a reference to last year in Unalakleet when King was in the lead and Mackey, who would go on to win, observed, "King should be worried."

Mackey laughed at King's comment this time.

"That's funny s---,'' he said.

Then he walked up to King and said, "I can't worry, Jeff."

"Pretty ballsy to say you're not worried at all,'' King said.

The exchange was all in good spirits, but it also made it clear this competition is heating up.

After King parked and snacked his team, he grabbed a plastic sled and hopped on the tailgate of a Chevy S10 pickup puttering down one of the few streets in this village on a bluff above the Yukon River. He rode up the hill to where the straw bales were.

He put a straw bale on his sled and rode it back to the team. He was clearly a musher in great spirits, a man pleased with his prospects.

"They've got lots of pep," King said. "Tired but very healthy. I've got some advantages (over Mackey), but we'll see what they do."

King did, however, admit he was impressed by Mackey blowing through the halfway point at Cripple and going another 110 miles before stopping to rest here.

"He's supernatural,'' King said. "(But) all mortals must slow down. If he wasn't here before me, I would think I was setting an Iditarod record."

Both King and Mackey declared their eight-hour rests here. Mushers are required to make one such stop along the Yukon. Whether others join the lead pair today or try to leapfrog them and take their rests later remains to be seen.

Either way, King thinks the strategy he and Mackey are employing is the right one. They arrived on a schedule that allowed their teams to rest during the warmth of the day. And with the days having been unseasonably warm -- mid-30s, sometimes pushing into the 40s -- that provides for the optimum in dog care.

"I think they eat better when it's warmer than when it's colder," King said.

They rest better, too. The only thing that isn't better is the travel on the trail. Dogs can easily overheat when running in warm weather, but that might be changing.

It was 20 degrees and starting to snow heavily here as King's team rested. Behind him, other teams were just arriving. The checkpoint was looking like it might get crowded by evening.