A few intermont areas in the north-west part of the province have outlet westward by Kla1nath river through the Cascade range and by Pitt river (upper part of the Sacramento) through the Sierra Nevada: a few basins in the south-east have outlet by the Rio Grande to the Gulf of Mexico; a much larger but still narrow medial area is drained south-westward by the Colorado to the head of the Gulf of California, where this large and very turbid river has formed an extensive delta, north of which the former head of the gulf is now cut off from the sea and laid bare by evaporation as a plain below sea-level.
Kiamath river, draining several lakes in the north-west part of the Basin Range province and traversing the Cascade Range to the Pacific, is apparently also an antecedent river.
The western slope of the Sierra Nevada hears fine forests similar to those of the Cascade Range and of the Coast Range, but of more open growth, and with the redwood exchanged for groves of big trees (Sequoia gigantea) of which the tallest examples reach 325 ft.
The Cascade Range enters from Canada, trending sotithward across the international boundary through ThePacifk Washington and Oregon to latitude 41; the Sierra Ranges.
The chief provinces of the Cordihleran region are: The Rocky Mountain system and its basins, from northern New Mexico northward, including all the mountains from the front ranges bordering on the plains to the Uinta and Wasatch ranges in Utah; the Pacific ranges including the Sierra Nevada of California, the Cascade range of Oregon and Washington, and the Coast range along the Pacific nearly to the southern end of California; and a great intermediate area, including in the north the Columbian lava plains and in the south the large province of the Basin ranges, which extends into Mexico and widens from the centre southward, so as to meet the Great Plains in eastern New Mexico, and to extend to the Pacific coast in southern California.
The most notable exceptions are in the case of a narrow strip west of the Cascade Range and of some of the higher mountain masses.
Foothills of the Cascade Range and in the Blue Mountains; this coal is suitable for steam and heating purposes but will not coke.
It was common to those tribes east of the Rocky Mountains, in the south-west and upper Columbia; but unknown apparently among the Eskimo, along the northwest coast, and on the Pacific coast west of the Cascade range and the Sierras, except among some few Californian tribes, or here and there in Mexico and southward.