For 11 more days Mackenzie struggled south-eastward against the Parsnip's current. The hungry paddlers boiled—what else?—wild parsnips with a long, deep V-shaped canyon with timbered sides scoured by avalanche chutes. On the morning of June 12 the explorers pushed to the end of a narrow lake nearly choked with driftwood fallen from the hillsides. Here, Mackenzie showed that remarkable ability to decipher the direction of watersheds within wildly tumbled terrain, a sense shared with other early travelers of the West. He was at the Continental Divide, and he knew it.
The waters of the driftwood-choked lake have as their ultimate destination the Arctic Ocean, via the Parsnip, Peace, Slave and Mackenzie rivers. That's why this lake's modern name is Arctic Lake, and there Mackenzie unloaded his canoe and portaged over "a beaten path leading over a low ridge of land of 817 paces to another small lake." This span of about seven football fields was labeled "Height of Land" on Mackenzie's 1801 map of his route, the classic name for a division of waters, though the elevation above sea level is only 2,500 feet. The portage ended at a smaller lake with a current at last flowing Mackenzie's way. After another short portage there was yet another narrow body of water, now appropriately named Pacific Lake, because it flows to that ocean by way of the McGregor and Fraser rivers.
Lewis could also read drainage divides. Lemhi Pass sits on the modern Idaho-Montana border in a jumble of ridges. Approaching the pass from the east on August 12, 1805, Lewis drank at a spring he knew would reach the Gulf of Mexico via the Missouri and Mississippi rivers. "We proceeded on to the top of the dividing ridge," he said, and on the opposite side soon "tasted the water of the great Columbia river." Heading back home through west-central Montana on July 7, 1806, Lewis climbed on horseback a partly wooded slope to arrive at what he identified at first sight as "the dividing ridge between the waters of the Columbia and Missouri rivers."
That's the pass (now named Lewis and Clark Pass) which Lewis later told Jefferson was the linchpin of "the most practicable rout which dose exist across the continent" by way of the Missouri and Columbia.14 The captain, alas, was a better reader of drainages than a prophet of transportation routes. No highway or railroad has ever crossed Lewis and Clark pass; the lonely saddle barely shows a jeep track.
Similarly, the three turquoise-colored lakes in the remote valley enclosing Mackenzie's Arctic-Pacific divide are today just scenic backwaters, hardly throbbing with commerce. As his trip to the Pacific unfolded Mackenzie knew his route was no good. Murderous rapids in Pacific Lake's outlet creek nearly ended his mission right there. When he finally reached the Fraser for a downstream cruise to the ocean he discovered a "violent" river threatening death at every bend. His decision to abandon the river and march directly westward won his nominal goal of reaching the sea, but that overland route offended the paddle-and-portage tradition of Canada's fur culture.
Heroic though it was, Mackenzie's journey produced no commercial return for the £1,500 it had cost the North West Company. He had reached the Pacific, but he knew that his route could not be used for trade, observed Walter Sheppe, a modern editor of Mackenzie's journal.15
Mackenzie's post-expedition career partly paralleled the experiences of Lewis and Clark. Like Lewis, the earlier conqueror of the Rockies suffered a bad case of writer's block in trying to compose a quick account of his trip. Like Clark, Mackenzie lived long after the big adventure, but neither of them ever went back West to re-experience its exhilarating rigors. "I think it unpardonable in any man to remain in this country who can afford to leave it," said Mackenzie in a post-expedition letter.16 Mackenzie left Fort Chipewyan and the Canadian north for good in 1794, and thereafter busied himself in fur trade matters at more comfortable stations in Montreal and London. He ultimately returned to Scotland where he died on March 11, 1820, at age 56.