By the first of December they had reached the Athabaska. Four days later they had come to a point on the river a little above Brulé lake, where the guide informed Thompson that owing to the lateness of the season, all thought of crossing the mountains with horses had to be given up. The greater number of the beasts were therefore sent back to Rocky Mountain House; four only were retained to ease the burden of the dogs. The thermometer now registered 32° below zero; and the party threw themselves into the work of building a rough shelter of logs to serve while they prepared sleds and snow shoes with which to complete their journey. At the end of the month they made a fresh start. Urged by the shouts and lashings of the voyageurs, the dogs with their burdens scurried along the ice of the river. In five days they came to the grassy ponds that marked its headwaters--the last possible pasturage for horses. Here, therefore, the poor animals were turned loose to survive the winter as best they could. Four days more brought the party to the height of land. The landscape, as far as the eye could reach, was clothed with a heavy mantle of gleaming snow. Round about towered the lofty peaks, their sides scarred by avalanches which had swept the slopes bare of trees and rocks in their descent. To the right lay an enormous glacier, a mass of blue-green ice, the eastern face of which was not less than two thousand feet in height. The night was fine, and the stars shone with such brilliance that one of the men told Thompson that he felt he could almost touch them with his hands. Early next morning they began the descent to the valley of the Columbia. On the eastern face of the mountains, the approach to the height of land had been a long and steady climb. To the west, the ground fell away in a series of abrupt slopes, so steep in places that it required sure footing to avoid a tumble. A short advance therefore was enough to produce an amazing difference in the climate. The snow which to the east of the mountains was thin and dry, here lay heavy and wet upon the ground; and they entered a forest of clean grown pine of gigantic height and girth. So heavy were the loads and so steep the slope that the dogs were unable to guide the sleds, and from time to time they came against the base of a pine tree with considerable force, dog on one side, sled on the other, so that they were disentangled with difficulty. To relieve the animals, Thompson had a portion of the loads removed from the sleds. The men grumbled as they were forced to lug these packs forward through the heavy snow. Finally after fifteen days' travel they arrived at the banks of the Columbia.