TOPOGEAPHICAL. — THE SIERRA NEVADA. 



11 



and heading in the peaks to the south of Silver Mountain ; then the Gala- 

 veras, a small stream with only 389 miles of catchment area, rising near the 

 grove of Big Trees of the same name; the Mokelumne, with 573 square 

 miles of drainage, rising a little to the east of Silver Mountain : the Co- 

 surnncs, with a catchment area just about equal to that of the Mokelumne, 

 but not heading on the main divide. North of this we have the extensive 

 drainage system of the American River with its numerous branches, or forks, 

 the most southern of which heads to the southwest of Carson Pass, on the 

 north slopes of the ridges of which the southern sides feed the Mokelumne ; 

 the most northerly branch, on the other hand, heads near Donner Pass, 

 about fifty miles farther north. The drainage area of the American River — 



a stream of great importance with reference to the subject of the present 

 volume — is 1,889 square miles. North of this again is Bear River, head- 



ing near Donner Pass, with 484 square miles of catchment area ; then the 

 Yuba, draining 1,329 square miles, also frequently to be mentioned in the 

 course of this volume. Finally we have the Feather, with numerous branches, 

 and a catchment area of 3,393 square miles, larger than that of any other of 

 the streams flowing down the western slope of the Sierra. The head of the 

 South Fork of the Feather is about four miles to the west of Pilot Peak, 

 while the head of the North Fork is at Lassen's Peak; the distance between 

 these two peaks being about sixty miles. From Mount Stanford north, the 

 water-shed of the Sierra presents a very irregular line, and the range is 

 equally broken and irregular. Most of the area in question is drained by 

 the North Fork of the Feather and its various branches, which run in nearly 

 parallel depressions having the general trend of the Sierra and unite with 

 the main stream which occupies a position tranverse to this, and in the lower 

 portion of its course, for a distance of forty miles, runs in a deep canon, re- 

 ceiving no important tributaries. The main axis of the Sierra is prolonged 

 from Mount Stanford through the Downieville or Sierra Buttes, Pilot Peak, 

 Clermont, Spanish Peak, Ben Lomond, and Butt Mountain to Lassen's Peak; 

 while nearly the whole drainage area of the North Fork of the Feather lies 

 to the east of this between the parallel ranges previously spoken of, which 

 tee some five or six in number, the total width of the western slope in this 

 portion of the range being about eighty-five miles. The elevation of the 

 dominant peaks in this region is not far from 9,000 feet; although Lassen's 

 Peak a little exceeds 10,500. The passes are all lower in proportion to the 

 height of the crest than farther south ; they range from 5,000 to 6,000 feet 



