264 Notes on Upper California. 



these slopes and the stratified earth and gravel of the plains may 

 therefore contain gold. But the parts more nearly in the vicinity 

 of the particular gold-bearing rocks, naturally prove most produc- 

 tive ; moreover, different layers in the soil, where they are a re- 

 sult of successive distribution, may differ widely in their yield. 

 Again, as above stated, the gold will be collected most largely 

 where the streams running through the earth or gravel have per- 

 formed to some extent the washing process, the gold settling 

 while the gravel is removed. 



On the east, stands the Sierra Nevada, covered largely with 

 snows, a perpetual source of water for streams. Consequently, the 

 Sacramento receives from this side numerous tributaries, and into 

 these tributaries a large number of rivulets flow along the ravines, 

 and into the rivulets numberless rills from the hill sides. The 

 last mentioned, from their steepness, carry the earth and what- 

 ever it contains into the ravines ; the rivulets, also steep, leave 

 along their bottoms part of the gold, but carry on another large 

 part and much earth ; while the large tributaries transport princi- 

 pally gravel and earth, leaving the gold to settle most abundantly 

 towards their upper parts, though distributing the finer grains along 

 their whole course. The American Fork, (emptying near Sutter's, 

 about ninety miles from the sea,) Feather river with its many 



affluents 



\ o j ji . 



from their sources in the mountains,, have long been engaged in 

 this washing process. Every winter's rains carry forward the 

 process anew, on a scale of great magnitude, and will hereafter 

 replace to some extent, what may be carried off in the other 

 months of the year. 



The Sacramento receives few tributaries from the west ; for 

 the coast mountains are not over 5000 feet in height, and the little 

 moisture they condense in summer flows down the western slopes 

 of the ridges. There are however some dry beds coursing through 

 the plains that are generally filled in the rainy season. 



The valley of the San Joaquin is a repetition, in nearly every 

 feature, of the Sacramento. The two properly constitute one 

 single north and south valley, 400 miles long, enclosed between 

 the Sierra Nevada and the Coast Range. 



The occurrence of alluvial gold commonly in flattened grains 

 arises directly from the forms it has in the rocks, and partly from 

 the wear and tear to which the whole is subjected. The abrading 

 and battering action of the moving waters and gravel, besides set- 

 ting loose the disseminated particles of gold, tends to reduce the 

 leaves or laminae to scales, breaks up the strings of metal to frag- 

 ments, and wears off the rough exterior of the larger lumps. 



