th Cerre. Crossing the Green River
valley, he proceeded along the south point of the Wind River range of
mountains, and soon fell upon the track of Mr. Robert Campbell's party,
which had preceded him by a day. This he pursued, until he perceived
that it led down the banks of the Sweet Water to the southeast. As this
was different from his proposed direction, he left it; and turning to
the northeast, soon came upon the waters of the Popo Agie. This stream
takes its rise in the Wind River Mountains. Its name, like most Indian
names, is characteristic. Popo, in the Crow language, signifies head;
and Agie, river. It is the head of a long river, extending from the
south end of the Wind River Mountains in a northeast direction, until it
falls into the Yellowstone. Its course is generally through plains,
but is twice crossed by chains of mountains; the first called the
Littlehorn; the second, the Bighorn. After it has forced its way through
the first chain, it is called the Horn River; after the second chain,
it is called the Bighorn River. Its passage through this last chain
is rough and violent; making repeated falls, and rushing down long and
furious rapids, which threaten destruction to the navigator; though a
hardy trapper is said to have shot down them in a canoe. At the foot of
these rapids, is the head of navigation; where it was the intention of
the parties to construct boats, and embark.

Proceeding down along the Popo Agie, Captain Bonneville came again in
full view of the "Bluffs," as they are called, extending from the base
of the Wind River Mountains far away to the east, and presenting to the
eye a confusion of hills and cliffs of red sandstone, some peaked and
angular, some round, some broken into crags and precipices, and piled up
in fantastic masses; but all naked and sterile. There appeared to be no
soil favorable to vegetation, nothing but coarse gravel; yet, over all
this isolated, barren landscape, were diffused such atmospherical tints
and hues, as to blend the whole into harmony and beauty.

In this neighborhood, the captain made search for "the great Tar
Spring," one of the wonders of the mountains; the medicinal properties
of which, he had heard extravagantly lauded by the trappers. After a
toilsome search, he found it at the foot of a sand-bluff, a little east
of the Wind River Mountains; where it exuded in a small stream of the
color and consistency of tar. The men immediately hastened to collect
a