ttled British boundary and the
disputed region of Oregon. Naturally, then, Americans wanted to know
what was to be found in this vast tract unknown to them, and when a few
bold spirits pushed out to the great mountains it was discovered that
fur-bearing animals existed in multitude. In the trapping of these and
the trading in their pelts a huge industry sprang up. In this trade
future millionaires laid their foundations.

The beaver were then the most profitable of all, and they were the most
abundant. The pelts were estimated by "packs," each of which consisted
of about eighty skins, weighing one hundred pounds, and worth in the
mountains from three hundred to five hundred dollars. The profits were
thus speedy and very great. In the search for the richest rewards the
trapper continually pushed farther and farther away from the "States,"
encroaching at length on the territory claimed by Spain, a claim to be
soon (1821) adopted by the new-born Mexican Republic. Trespassing on the
tribal rights of Blackfoot, Sioux, Ute, or any other did not enter
into any one's mind as something to be considered. Thus, rough-shod the
trapper broke the wilderness, fathomed its secret places, traversed its
trails and passes, marking them with his own blood and more vividly with
that of the natives. Incidentally, by right of their discoveries and
occupation of the wilderness, much of it became by the law of nations a
part of the lands of the United States, though still nominally claimed
by Mexico. Two years after the return of the famous Lewis-and-Clark
expedition, Andrew Henry "discovered" South Pass (1808), and led his
party through it into the Green River* Valley. His discovery consisted,
like many others of the time, in following up the bison trails and the
highways of the natives. The latter, of course, knew every foot of the
whole country; each tribe its own special lands and more or less into
and across those of its neighbours.

* The name Green River was used as early as 1824, and was probably
derived from the name of the early trapper. Till about 1835 it was
usually called by the Crow name, Seedskeedee.

By the time the third decade of the nineteenth century was fairly begun
the trappers were crossing in considerable numbers from the headwaters
of the Missouri and the Platte into the valley of the Colorado and the
Columbia, and as early as 1824 one of the most brilliant figures of
this epoch, General Ashley,* having previo