834 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Through the Rocky mountains, there is one in the south lati 

 tucle, 35° N. at the head of the Pecos river, 30 miles wide, and 

 7,000 feet above tide. There is another, a little further west, 

 through the Sierra Madre — Camino del Opispo, 8,250 feet high, 

 which opens a passage into the Imsin of the Pacific. Farther north 

 iu the parallel of 38° N. there is the Huerfano pass of 6,099 feet 

 elevation, and the Sangre de Christo pass, 9,219 feet above the Gulf 

 of Mexico. In latitude 41° N. there is Bridger's pass, 7,254 feet, 

 and one degree further north, there is the famous South pass, dis- 

 covered by Lewis and Clark, 7,490 feet elevation. One can stand 

 in this grand portal to the Pacific coast, and scanning the entire 

 horizon find not a mountain in sight, only low, rocky hills, cut 

 through by waters flowing east and west. The Sierra Nevada 

 have the Madeline pass, 4,079 feet high, and the plateau around 

 Lake Abert 40 miles wide of 5,200 feet elevation. These are in 

 the north, while south there is the Cajon pass, only 3,300 feet 

 above the waters of the Pacific. The coast range is broken through 

 by the Sacramento, Klamath, Columbia and Frazier rivers. The 

 Cascades by Lewis and Clark's forks of the Columbia. 



These groups of mountains, thus hastily described, fill up about 

 1,500 miles in width of the United States, at the point of their 

 greatest breadth, and average about 500 miles wide They form, 

 then, the most prominent feature of the Continent. The Rocky 

 mountains are the crest of the Continent. By it the east and west 

 slopes were formed of the grand hydrographical basins of the 

 Atlantic and Pacific. The latter, narrow and precipitous ; the 

 former, long, wide, and of gentle decline. In an air line from 

 their culminating point, the Colorado and Columbia rivers flow 

 westward 750 and 650 miles, to find the level of the ocean; the 

 Platte and the Missouri rivers flow from the same point, 1,700 and 

 1,850 miles, to find the same level. 



Lookinjr over the western basin, it is broken into a confused 

 labyrinth of mountains and valleys ; but looking north or south 

 over the eastern, it is wholly unlike the former, for it is unbroken 

 by any range of mountains from the Gulf of Mexico to the Arctic 

 sea, a distance of nearly 3,000 miles. 



At the lioundary line between Her Majesty's dominions and our 



own, a low water-shed extends ofl' eastward, and forms a part of 



he Coteau du Missouri, and then curving gently southwards enters 



the State of Minnesota ; it now curves around the head of Lake 



Superior, M'here it becomes a range of hills or mountains, and 



