the autumn of 1823 and the spring of the next year, one of his
agents erected a post at the mouth of the Bighorn, and sent out his
trappers through the Green River valley, possibly even to Great Salt
Lake. A detachment of this party found the gateway of the Rocky
Mountains, through the famous South Pass by way of the Sweetwater
branch of the north fork of the Platte. This pass commanded the
routes to the great interior basin and to the Pacific Ocean. What
Cumberland Gap was in the advance of settlement across the
Alleghenies, South Pass was in the movement across the Rocky
Mountains; through it passed the later Oregon and California trails
to the Pacific coast.

On the lower Missouri and at various places in the
interior,[Footnote: See map, p. 114; Chittenden, Am. Fur Trade, I.,
44-51 (describes posts, etc.).] stockaded trading-posts were erected
by the Rocky Mountain Fur Company and its rival, the American Fur
Company. In these posts the old fur-trade life of the past went on,
with French half-breed packmen and boatmen, commanded by the
bourgeois. But in some of the best trading-grounds, the savages
declined to permit the erection of posts, and so, under Ashley's
leadership, bands of mounted American trappers, chiefly Kentuckians,
Tennesseeans, and Missourians, were sent out to hunt and trade in
the rich beaver valleys of the mountains. The Rocky Mountain
trappers were the successors to the Allegheny frontiersmen, carrying
on in this new region, where nature wrought on a vaster plan, the
old trapping life which their ancestors had carried on through
Cumberland Gap in the "dark and bloody ground" of Kentucky.

Yearly, in June and July, a rendezvous was held in the mountains, to
which the brigades of trappers returned with the products of their