height toward the south, near the
line between New Mexico and Colorado. Here is situated Raton Pass,
an ancient Indian highway from the valley of the Arkansas to the
Rio Grande. In the early half of the last century this trail was
much used by the caravans of traders and came to be known as the
Santa Fe trail.

[Illustration: FIG. 93.--ON THE CONTINENTAL DIVIDE IN SOUTHWESTERN
WYOMING]

In the early days of the American occupation of California, the
Santa Fe trail became an important route to the Pacific. From the
Mexican town of Santa Fe it led down the valley of the Rio Grande,
following the old road to Mexico, and then turned west across the
broad plateau of the continental divide, not far from the present
course of the Southern Pacific Railroad. Passing Tucson, the road
kept near the course of the Gila River to Fort Yuma, and then led
over the Colorado Desert to Los Angeles. This path avoided all
the high mountains, but much of it lay across deserts, where the
heat and scarcity of water made it an impracticable route for the
emigrants.

One not acquainted with the physical geography of the West might
wonder why the gold-seekers on their way to California did not make
use of the Missouri River, which, except for the Great Falls, was
navigable for small boats to the very base of the Rocky Mountains.
A partial explanation is found in the report of the hardships endured
by the Lewis and Clark exploring expedition, and later by the Astor
party, which went out to found a fur trading post at the mouth of
the Columbia. It had been supposed that after once crossing the
continental divide it would be an easy matter to embark upon some
stream and float down to the Pacific Ocean. The parties referred to
became lost in the defiles of the mountains, and when they finally
reached the Snake River it was only to find that rapids and waterfalls
continually obstructed navigation. Although there was in most places
plenty of water upon this northern route, yet the mountains were
impassable for wagons.

Because of these conditions the emigrants started out boldly across
the plains, following the general course of the Platte River, and
crossing the Rocky Mountain divide at the South Pass in western
Wyoming, a place famous in its day. At this point those who were
going to Oregon turned northwestward to Fort Hall, a trading post
of the Hudson Bay Company. From here they crossed southern Idaho,
keeping near the course of the Snake Ri