It was a critical moment. Springing to his horse, Thompson galloped to the nearest knoll, from which with his glass he scanned the horizon on every side. Not a vestige of wood was in sight, but far to the north-west his eye caught what seemed to be the tops of a clump of trees. On this he took a bearing with his compass, and called to the party to follow him, which after some hesitation they made up their minds to do. Meanwhile the wind came on with increasing force, and the darkness closed in before they could see whether it was really a wood to which their painful and tedious march led. However, they kept in file and close together, and the dogs gave no trouble. It was black night before they finally reached the wood. Utterly wearied, the men hurriedly threw up their canvas and sought shelter from the storm. The blizzard continued through the next day, and the men were too exhausted to proceed. They remained in camp with nothing but the meat of two tough old bulls to relieve their hunger. The day following two of the three horses went lame, their hoofs eaten away by the hard crusty snow. Luckily they encountered a small party of Assiniboines on their way to McDonnell's house to trade, and were able to send the horses back with them to the fort, purchasing dogs from the Indians in their stead. Two days later they met another party of Indians, and from them got a good meal. These Indians warned them that the Sioux were in waiting at the Dog Tent Hills; and no offer would induce anyone of them to go forward with the party as a guide. They were now in the neighbourhood of Turtle Mountain, and Thompson had taken sole command. Another gale, another blizzard, and another march till nightfall brought them to the hill. On this occasion again the compass proved a trusty guide. In the darkness, Thompson's face brushed against the overhanging branch of a tree, and he knew that he had guided his men safely to the wood. Thus they continued as far as the Dog Tent Hills, near the elbow of the Souris. On approaching the broken country, Thompson espied a long line of horsemen descending the slope and moving off to the south. It was the Sioux, who had made up their minds that no traveller would venture forth in such tempestuous weather. Thompson signalled his men to throw themselves flat on the ground. This they did, and remained unperceived until the enemy was out of sight. They then entered the hills, and while they rested and hunted, cut tent poles and firewood for the dash across the barren plain. The fifty miles that still divided them from the waters of the Missouri were passed without adventure, and they arrived, tired but triumphant, at the upper village of the Mandans after a journey of thirty-three days.