o 



S2 Observations on the Physical Geography 



latitude 39° 17' 12", "the usual emigrant pass," the height 

 was 7,200 feet. The same range where passed by Emory, east of 

 San Diego just north of 33°, was little over 3,000 feet in alti- 

 tude. The same mountains continued south, constitute the 

 range of heights forming the Californian peninsula. 



We pass now from these brief remarks upon the great dividing 

 range of the territory to the sections east and west. 



2. The mountains of the Eastern section have in general a par- 

 allelism with the Rocky chain, or else a direction transverse to this 

 course. The Blue mountains, lie nearly parallel with the Cas- 

 cade range, and bound the region of the Southern fork of the 

 Columbia (Lewis or Snake river) on the west. North of this 

 fork the range ceases ; but beyond the northern Columbia other 

 ridges continue its northward course. These mountains are eight 

 to nine thousand feet high, and four thousand feet at the pass. 

 The Grand Rond is a large circular valley in the mountains 

 measuring fifteen miles by twelve in its diameters; it is a fertile 

 prairie shut in by high walls of basalt and situated about three 

 thousand 4 feet above the sea. 



South of the Blue range, between the districts of Snake river 

 and the Colorado, a vast territory four hundred miles in longitude 

 by two hundred and fifty in latitude, is called by Fremont, u the 

 Great Basin 7 ' — a region of lakes without outlets, of few rivers, 

 and these without mouths, of salines and salt efflorescences, — yet 

 of some green spots amid wide regions of aridity. Even here, ac- 

 cording to the map of this explorer,* the mountain ridges of the 

 Basin, rising two to five thousand feet above its level, have gene- 

 rally a north and south direction. The courses of the limiting 

 ranges of this great area are yet to be determined. Crossing the 

 Sierra Nevada, Fremont found the western or Sacramento foot, 

 five hundred feet above the sea, the eastern four thousand feet ; 

 and the whole of this " Great Basin" (excluding its mountains) 

 from east to west ranged in altitude above the sea from four to 

 six thousand feet. The Great Salt Lake near its Eastern limit, 

 is 4,501) feet above the ocean, and Pyramid lake,f a beautiful 

 body of water twenty-five miles long, near the eastern foot of the 

 Sierra Nevada, is 4,890 feet. 



This Basin is therefore a peculiar feature of the western terri- 

 tory. Instead of the usual western slope of the Great Rocky 

 Range, there is here no proper descent to the westward of the Salt 

 m Lake, until crossing the Sierra Nevada. This is seen in the fol- 



lowing profile section reduced from Fremont's. 



The contrast with other parts is well show- ~ y - r 



with the sections on pages 376, 377, one along the Columbia, and 

 the other by the river Gila* 



compar 



7.. Mem. upon Upper California. 1848. 

 Journal, ii ser« ill 201, 1847. 



