GENERAL FRATURES. 613 
thousand miles. ‘The whole is literally a vast shed, whose summit 
divides the waters that flow on either side. 
Nearly all the rivers of America, excepting those east of the Missis- 
sippi, take their rise in this chain. We observe the Rio Grande del 
Norte and Arkansas on one side, and the Colorado on the other, 
draining the same heights; the Nebraska, Yellowstone and Missouri 
flowing from the very snows that form the head waters of the Lewis 
or Snake; while the Saskatchawan, whose waters reach the Atlantic 
through the Great Lakes and the St. Lawrence, and the Athabasca, 
which runs by the Slave Lake to the Arctic Ocean, slope off from the 
heights which contribute on the west in the same vicinity to the 
Columbia and to Fraser’s River. 
From these preliminary observations we pass to the consideration 
of the region west of the dividing summit of the Rocky Mountains, 
and particularly that portion belonging to the territory of the United 
States. 
GENERAL FEATURES. 
The coast, the mountains, the rivers, and the plains, are subjects 
_ severally demanding a brief notice. 
A. Features of the Coast. 
The outline of the coast of western North America, from the Cali- 
fornia Gulf to Puget’s Sound, has few indentations. The harbour of 
Monterey is a small open roadstead. ‘The Bay of San Francisco is 
a deep gulf of irregular form, consisting mainly of two broad arms, 
one twenty-five and the other thirty-five miles long, opening upon 
the sea through a single channel a mile wide and five long. Sacra- 
mento River flows into the northern arm, and the San José into 
the southern. Between San Francisco and the Columbia, are the 
Clammat and Umpqua Rivers, and at the mouth of the latter there 
is anchorage for vessels drawing not over eight feet. ‘The Columbia 
has a mouth seven miles in width, and the waters within afford good 
anchorage, though reached by a somewhat difficult channel, which is 
wholly impassable in bad weather. ‘The Chekelis River, sixty miles 
to the north, empties into a large shallow bay called Gray’s Harbour, 
the bar of which prevents the ingress of vessels drawing over ten feet. 
From the Straits of De Fuca north, there is a total change of cha- 
racter. The continent is abruptly narrowed a hundred and fifty 
miles, and Vancouver’s Island appears as the proper continuation of 
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