The bend of the Missouri had been foreseen by the statesmen of the twenties as the limit of American advance. It might have continued thus had there really been nothing beyond it. But the profits of the trade to Santa Fé created a new interest and a connecting road. In nearly the same years the call of the fur trade led to the tracing of another path in the wilderness, running to a new goal. Oregon and the fur trade had stirred up so much interest beyond the Rockies that before Kearny marched his army into Santa Fé another trail of importance equal to his had been run to Oregon.
The maintenance of the Indian frontier depended upon the ability of the United States to keep whites out of the Indian Country. But with Oregon and Santa Fé beyond, this could never be. The trails had already shown the fallacy of the frontier policy before it had become a fact in 1840.
The Santa Fé trade had just been started upon its long career when trappers discovered in the Rocky Mountains, not far from where the forty-second parallel intersects the continental divide, an easy crossing by which access might be had from the waters of the upper Platte to those of the Pacific Slope. South Pass, as this passage through the hills soon came to be called, was the gateway to Oregon. As yet the United States had not an inch of uncontested soil upon the Pacific, but in years to come a whole civilization was to pour over the upper trail to people the valley of the Columbia and claim it for new states. The Santa Fé trail was chiefly the route of commerce. The Oregon trail became the pathway of a people westward bound.
In its earliest years the Oregon trail knew only the fur traders, those nameless pioneers who possessed an accurate rule-of-thumb knowledge of every hill and valley of the mountains nearly a generation before the surveyor and his transit brought them within the circle of recorded facts. The historian of the fur trade, Major Hiram Martin Chittenden, has tracked out many of them with the same laborious industry that carried them after the beaver and the other marketable furs. When they first appeared is lost in tradition. That they were everywhere in the period between the journey of Lewis and Clark, in 1805, and the rise of Independence as an outfitting post, in 1832, is clearly manifest. That they discovered every important geographic fact of the West is quite as certain as it is that their discoveries were often barren, were generally unrecorded in a formal way, and exercised little influence upon subsequent settlement and discovery. Their place in history is similar to that of those equally nameless ship captains of the thirteenth century who knew and charted the shore of the Mediterranean at a time when scientific geographers were yet living on a flat earth and shaping cosmographies from the Old Testament. Although the fur-traders, with their great companies behind them, did less to direct the future than their knowledge of geography might have warranted, they managed to secure a foothold upon the Pacific coast early in the century. Astoria, in 1811, was only a pawn in the game between the British and American organizations, whose control over Oregon was so confusing that Great Britain and the United States, in 1818, gave up the task of drawing a boundary when they reached the Rockies, and allowed the country beyond to remain under joint occupation.