In the spring he took horse and rode overland to Fort Augustus, and thence south along the Edmonton-Calgary line to a point just short of the present town of Lacombe. Turning west, he struck the Clearwater near its mouth and found himself at Rocky Mountain House. While he himself descended the North Saskatchewan to the elbow, making a survey as he went, he sent four French Canadians south to the Red Deer river, with orders to follow it to its junction with the main stream of the South Saskatchewan. A short distance below Rocky Mountain House, he found a party of Hudson's Bay men encamped for building. The English, as well as the Canadians, were bent on crossing the Great Divide; and it would be a serious blow if they were allowed to anticipate the North-Westers in so doing. Accordingly, on his return to Rocky Mountain House, Thompson brought with him Duncan McGillivray from down the river, in order that he might have assistance in pressing forward his explorations. Along with McGillivray, he rode across to the Red Deer river, where he found a camp of Piegans. A short stay among them was enough to lull their suspicions; and Thompson was then able to ride twenty-two miles west to the foot of the mountains, where he expected to meet a band of Kootenays. These he found, twenty-six strong. With their women and children they had crossed the divide to meet the white traders. These Kootenays were the first of the British Columbia Indians whom Thompson had encountered. He warned them of the presence of the Piegans only a few miles east, and sent them back across the mountains. In order to avoid the Piegans, they travelled by way of the North Saskatchewan and succeeded in reaching their homes unobserved. Meanwhile, with McGillivray and four men on horseback, Thompson crossed the Red Deer river and rode still further south to the banks of the Bow, not far from Calgary. This stream he surveyed as far east as the bend and westward to Exshaw at the foot of the mountains. McGillivray then made a traverse across from the north fork of the Saskatchewan to the valley of the Athabaska, the results of which were carefully incorporated in Thompson's notes. Thompson himself spent the rest of the winter at Rocky Mountain House, trading with the natives and taking observations to fix the location of the post. When spring opened, he resolved to attempt a journey into the mountains by land. With a party of eight men and an Indian guide, he started westward from Rocky Mountain House. In the narrow valley of the Sheep river, the horses could go no further; and as the guide knew of no other route, they returned to the post. A second attempt, this time by canoe up the Saskatchewan, was equally unsuccessful because of the floods on the river. When Thompson returned to eastern headquarters in the spring of 1802, he was not yet able to report that he had opened a practicable route to the west of the Rockies.