Early Friday, the leaders of the Iditarod Trail Sled Dog Race gathered in Anvik, the first checkpoint on the mighty Yukon River after tough push from the abandoned gold-mining town of Iditarod. The 2013 race was turning into a poster child for global warming as snow melted, the trail worsened and mushers stripped down extra layers of clothing.

Norwegian rookie Joar Liefseth Ulsom wore homemade rain boots, essentially plastic bags over his boots, as he went through his chores in the Anvik checkpoint. Nearly a shoo-in for rookie of the year, Ulsom is running a fabulous race, consistently among the Top 10.

By 2 p.m., 17 mushers had arrived in Anvik, and the top five were already in Grayling, one checkpoint beyond Anvik.

Big Lake veteran Martin Buser continued to lead. Not only was he at the front of the pack, out of Grayling at 12:52 p.m., but he was the only musher among the top 14 to have completed his mandatory eight-hour rest on the Yukon, something all mushers must do between Anvik and Kaltag, the final Yukon River checkpoint before the trail turns west and heads for the Bering Sea coast.

Before Buser left Anvik, he and another four-time champion, Lance Mackey of Fairbanks compared notes on how the race was proceeding. Mackey was in 11th place Friday afternoon, with a dozen dogs still in his team.

Once all the mushers finish their Yukon River layovers, it will be easier to tell who's actually ahead -- and by how much.

For more updates, check out Alaska Dispatch's Iditablog