nder that Captains
Lewis and Clark were in doubt as to which way they should go in
order to reach the Columbia. They first attempted to go down the
Salmon River, but soon gave up this project. They turned about
and crossed the mountains to the Bitter Root River, which flows
north and empties into Lake Pend d'Oreille through Clark's Fork
of the Columbia.

After going down the Bitter Root for a short distance they turned
west again across the Bitter Root Mountains and came out upon the
head waters of the Kooskooskie River. Unable to follow its canons,
they wandered to the north among the mountains. At this time their
sufferings were intense. Food became so scarce that they were obliged
to eat their horses. After many weary days they again reached the
stream, but this time at a point where it was navigable. They floated
down to its junction with the Lewis or Snake River, where the growing
city of Lewiston now stands. At this point they met the Nez Perces
Indians, who assisted them in every possible way.

[Illustration: FIG. 69.--CELILO FALLS, COLUMBIA RIVER]

The party continued down the Snake River in canoes until they finally
reached the Columbia. The difficulties of navigation were great,
for at intervals of every few miles the river was broken by rapids
through which it was dangerous to take the canoes. By treating
the Indians kindly, the party succeeded in trading with them for
such articles of food as horses and dogs. They also obtained some
salmon. The presence of this fish in the streams gave them the
first assurance that the Pacific slope had been reached. Along
the Columbia River salmon was one of the chief articles of food
for the Indians.

At Celilo Falls, a short distance above the present city of The
Dalles, the travellers found great difficulty in proceeding, as
the canoes and loads had to be carried, or "portaged," around the
falls. Lewis and Clark called these the Great Falls of the Columbia
(Fig. 69).

As the canoes floated down through the magnificent canon by which
the Columbia passes the Cascade Range, they encountered another
rapid, now known as the Cascades of the Columbia. This rapid is
due to a great landslide which has formed a dam across the river.
Captain Lewis speaks of the broken trunks of trees rising from
the water above the dam, a fact which would lead one to suppose
that it had not been very long since the slide occurred.

Below the Cascades the party soon began to notice the infl