472 



a succession of basins: they are separated by 

 hills little striking to the eye of the traveller 

 because they rise but 250 to 400 toises above 

 the surrounding plains. These basins are some- 

 times closed, like the valley of Tenochtitlan, 

 where lie the great Alpine lakes, and sometimes 

 present traces of ancient ejections, destitute of 

 water. 



Between lat. 33° and 38°, the Rio del Norte 

 forms, in its upper course, a great longitudinal 

 valley ; and the central chain seems here to be 

 divided into several parallel ranges. This dis- 

 position continues, towards the north, in the 

 Rocky Mountains*, where, according to the 

 intrepid labors of Captain Pike, Major Long, 

 and Dr. Edwin James, between the parallels of 

 37° and 41°, several summits covered with eter- 

 nal snows (Spanish Peak, James Peak, and Big- 

 horn)^, are from 1600 to 1870 toises of abso- 



* The Rocky Mountains have been known at different 

 periods by the names of Chypewyan, Missouri, Columbian, 

 Caous, Stony, Shining and Sandy Mountains. (See Long. 

 Exped. Vol. ii, p. 405 ; and Humb. Per. Nar. Vol. iv, p. 9.; 



f These peaks of amphibolic granite, do not form three 

 insulated mountains ; each peak has several pointed sum- 

 mits. Spanish Peak, (lat. 37° 20' long. 106 9 55') is placed 

 between the source of the northern branch (Northern Fork} 

 of Canadian River, and the source of the Arkansas 5 it is 

 perhaps the Sierra de Taos of the ancient Mexican maps, 

 N.N.E. of Taos, (the Tous of Mellish, and of so many maps 



