north or to the west. In 1789 Mackenzie set out from Fort Chipewyan with a small party in canoes and, circling Great Slave Lake, discovered a river flowing out of that lake toward the north. He descended the river to the Arctic Ocean, making the entire journey in forty days. Returning, he immediately organized the trade along the line thus opened. Since he had found the estuary of Mackenzie River choked with ice in July, and since he observed in the west a chain of mountains running still farther north, Mackenzie became convinced of the impracticability of a northwest passage around the continent. He therefore came to believe in the extreme desirability of finding a way through or across the continent to the Pacific, an idea we saw the British admiralty suggesting in its instructions to Captain Vancouver about the same time.
Accordingly, Mackenzie proposed to reach the Pacific by ascending Peace River which flows into Lake Athabasca from the west, and from its sources to cross to some west-flowing stream. Wintering near the Rocky Mountains on Peace River in 1792-3, he resumed his journey May 9, 1793, and on the 18th of June discovered a river having a westerly course. This he descended for twenty-five days when the difficulties of navigation impelled him to leave the river. By following an old trail and afterward descending another smaller stream with a more direct course, he and his party of ten intrepid woodsmen reached the Pacific in latitude 52° 20' at a place which had been recently surveyed by Vancouver and by him called Cascade Canal.
