O GENERAL VIEW OF THE GEOGRAPHY. 



lofty ridges, separated only by narrow valleys, or plains of moderate width. 

 The country at the base of the chain, on the Atlantic side, is probably 

 nowhere less than four thousand feet above the level of the sea ; and that 

 on the Pacific side is doubtless much higher. 



The most elevated portion of the Rocky Mountains is about the 54th 

 degree of latitude, where the chain turns towards the west ; several peaks 

 in that vicinity have been ascertained to rise more than sixteen thousand 

 feet above the ocean level. Many points, which are undoubtedly more 

 than ten thousand feet in height, have been found in the portion of the 

 dividing ridge called the Wind River Mountains, near the 42d degree of 

 latitude, and farther south, in Long's Range, where the sources of the 

 Arkansas River are situated. 



Among these mountains, nearly all the greatest rivers in North America 

 have their sources. Within a hundred miles of the point where the chain 

 is crossed by the 41st parallel, rise — on the eastern side — the Missouri, 

 the Yellowstone, the Platte, and the Arkansas, the waters of all which are 

 carried through the Mississippi into the Mexican Gulf, and the River 

 Bravo del Norte, which falls into the same arm of the Atlantic ; while — on 

 the western side — are found the springs of the Lewis, or Snake, the princi- 

 pal southern branch of the Columbia which enters the Pacific, and those 

 of the Colorado, which terminates in the head or northern extremity of 

 the Californian Gulf. The sources of the Platte, and those of the Green 

 River, the largest head-water of the Colorado, are situated at opposite ends 

 of a cleft, or transverse valley, in the Rocky Mountains, called the South 

 Pass, in latitude of 42 degrees 20 minutes, which seems destined to be 

 the gate of communication between the Atlantic and the Pacific regions 

 of the continent. In another great cleft, called by the British traders 

 the Punch Bowl, near the 53d parallel, overhung by the highest peaks 

 of the chain, the northern branch of the Columbia issues from a lake, 

 situated within a few feet of another lake, from which runs the west 

 branch of the Athabasca, one of the affluents to the Mackenzie; and at a 

 short distance south rises the Saskatchawine, which takes its course east- 

 ward to Lake Winnipeg, and contributes to the supply of Hudson's Bay. 

 In many places between the 42d and the 50th degrees of latitude, the 

 upper streams of the Missouri lie very near to those of the Columbia ; but 

 no gap or depression, which appears to offer facilities for travelling or 

 transportation of merchandise, has been discovered in that part of the 

 dividing chain. 



The ridges between the Rocky Mountains and the great westernmost 

 chain which borders the Pacific coast, appear to be all united with one or 

 both of those chains, and to run, for the most part, in the same general 

 direction, from south-east to north-west. The most extensive of these 

 intermediate ridges, called the Snowy Mountains, is believed to stretch 

 uninterruptedly from the Rocky Mountains to the westernmost range, and 

 even to the Pacific, nearly in the course of the 41st parallel of latitude, 

 dividing the regions drained by the Columbia, on the north, from Cali- 

 fornia, on the south. Another ridge, called the Blue Mountains, extends 

 northward from the Snowy Mountains to the 47th parallel, bounding the 

 valley of the Snake or Lewis River, the southern branch of the Columbia, 

 on the west. A lofty ridge also runs from the westernmost chain, near 

 the 48th degree of latitude, northward, to the Rocky Mountains, which it 

 joins near the 54th degree, separating the waters of the northern branch 



