ROHN, Alaska -- Linwood Fiedler seized a substantial lead in the Iditarod Trail Sled Dog Race on Monday, arriving in Rohn nearly three hours ahead of his closest challenger.

Fiedler arrived at the checkpoint 272 miles into the race at 4:38 p.m. Three-time winner Martin Buser was second, arriving at 7:25 p.m.

Fiedler, who lives in Willow and was runner-up in the Iditarod last year, pushed through the heat of a sunny afternoon at a swift pace. He made the 48-mile run from Rainy Pass to Rohn in 3 hours, 45 minutes.

Buser was even faster, covering the distance in 3:13 after taking just two minutes at Rainy Pass.

The leaders are 850 miles from the finish in Nome.

Norwegian musher Harald Tunheim was third. He left Rainy Pass at 4:04 p.m., a few minutes ahead of Charlie Boulding and Buser.

Boulding, of Manley, was first into Rainy Pass at 10:56 a.m. Monday. He rested more than five hours before chasing the leaders. Boulding left at 4:08 p.m., two minutes after Tunheim. He said the trail was the fastest he'd seen in 10 Iditarods.

Buser, a three-time Iditarod champion from Big Lake, left Rainy Pass at 4:12 p.m.

Behind him was Ramy Brooks of Healy, who left at 4:48 p.m. after a rest of more than four hours. Three-time winner Jeff King left at 5:10 p.m. with six hours of rest.

John Baker of Kotzebue followed at 5:14 p.m. His dogs also had about six hours to recoup their strength. Behind him was Ramey Smyth at 5:52 p.m. In ninth place was Jerry Riley, the 65-year-old Nenana musher who won in 1976. He left Rainy Pass at 5:52 p.m. after a six-hour break. DeeDee Jonrowe was out at 6:18 p.m.

Also out of Rainy Pass were Vern Halter, five-time winner Rick Swenson, Sonny Lindner, Jim Lanier, and Sonny King.

Well back in the pack was Montana musher Doug Swingley, who has won three consecutive races. Swingley was still in Finger Lake on Monday evening, 78 miles behind the leader in 41st place. But Swingley had a rested team with the cool night ahead. He arrived in Finger Lake just after noon.