In an audio update on his website Monday, Lonnie Dupre of Grand Marais said he was making progress in his attempt to become the first person traveling solo to reach the summit of Alaska's Mount McKinley in January. Dupre was flown from Talkeetna, Alaska, to the Kahiltna Glacier, the starting point for McKinley climbs, on Friday afternoon.

Climbers typically start on the glacier at about 7,200 feet. On Monday, Dupre filed his audio report from a snow trench where he had spent the night at about 8,000 feet. The summit of Mount McKinley, North America's highest peak, is 20,320 feet.

Dupre, 49, said his progress on Sunday was a "hard slog" because the snow crystals are cold and sharp, making it difficult to pull his 150-pound sled with food and supplies. He's also attached to a 14-foot ladder, which he wears to minimize the chance of his falling into a crevasse hidden beneath a thin layer of snow.

Dupre reported on Sunday that temperatures had reached 20 below zero on the glacier, but Monday morning the temperature was zero, he said. Winter conditions on Denali are usually fierce, with winds up to

100 mph and temperatures of 50 below zero. Because of the wind and cold, Dupre is not using a tent on the climb. Instead, he'll spend his nights -- and weatherbound days -- in shallow snow trenches. He has only about 5½ hours of daylight each day, he said.

"I leave in the dark in the mornings, and I get done in the dark," he said Monday.

He said it took him nearly two hours to dig his snow trench on Sunday night.

Only nine expeditions totaling 16 people have reached the summit of Denali in winter. Six deaths resulted from those climbs. Only one team, comprising three Russian climbers, has made the summit in January.

Dupre has more than

25 years of polar exploration experience, including the circumnavigation of Greenland and two expeditions to the North Pole.

Early in the expedition, Dupre will travel on skis. As the terrain steepens, Dupre will switch to crampons (sharp spikes that fit over boots) and a backpack.

Dupre will be in daily contact from the trail with a support team stationed in Talkeetna, Alaska. From there, daily blog entries, photographs, video and audio posts will be sent to support the expedition's website,