breadth, bounded on the east by the Sierra Nevada, and on the west by
the Pacific. In speaking of Upper California this strip of country is
what is generally referred to.

The largest river of Upper California is the Colorado or Red, which has
a course of about 1000 miles, and empties into the Gulf of California
in latitude about 32 degrees north. But little is known of the region
through which this stream flows. The report of trappers, however, is
that the river is _canoned_ between high mountains and precipices a
large portion of its course, and that its banks and the country
generally through which it flows are arid, sandy, and barren. Green and
Grand Rivers are its principal upper tributaries, both of which rise in
the Rocky Mountains, and within the territories of the United States.
The Gila is its lowest and largest branch, emptying into the Colorado,
just above its mouth. Sevier and Virgin Rivers are also tributaries of
the Colorado. Mary's River rises near latitude 42 degrees north, and
has a course of about 400 miles, when its waters sink in the sands of
the desert. This river is not laid down on any map which I have seen.
The Sacramento and San Joaquin Rivers have each a course of from 300 to
400 miles, the first flowing from the north and the last from the
south, and both emptying into the Bay of St. Francisco at the same
point. They water the large and fertile valley lying between the Sierra
Nevada and the coast range of mountains. I subjoin a description of the
valley and river San Joaquin, from the pen of a gentleman (Dr. Marsh)
who has explored the river from its source to its mouth.

"This noble valley is the first undoubtedly in California, and one of
the most magnificent in the world. It is about 500 miles long, with
an-average width of about fifty miles. It is bounded on the east by the
great Snowy Mountains, and on the west by the low range, which in many
places dwindles into insignificant hills, and has its northern terminus
at the Strait of Carquines, on the Bay of San Francisco, and its
southern near the Colorado River.

"The river of San Joaquin flows through the middle of the valley for
about half of its extent, and thence diverges towards the eastern
mountain, in which it has its source. About sixty miles further south
is the northern end of the Buena Vista Lake, which is about one hundred
miles long, and from ten to twenty wide. Still farther south, and near
the western side of the valley,