338 RESOURCES OF CALIFORNIA. 



nearer the bottom land of the valleys. Gold is rarely found 

 in loam or pure clay, but usually in the strata of gravel or 

 boulders, next the bed-rock, and in the deepest depressions, as 

 in the beds of streams. 



265. Dead Rivers. But those places which are now, 

 were not in the Pliocene era, the beds of rivers. California 

 has numerous dead rivers or channels, once used by large 

 streams of water, but now filled up with gravel ; and on ac- 

 count of their auriferous wealth they have been discovered, 

 traced out, and examined with an industry and care not be- 

 stowed upon similar extinct streams in any other part of the 

 world. Indeed, it is doubtful whether dead rivers so wonderful 

 in character could be found elsewhere. Some of these channels 

 are covered with mountains of basalt, among which the Tuol- 

 umne Table Mountain, thirty miles long and half a mile 

 wide, is the most celebrated. In the Pliocene age, a river ran 

 nearly in the course of the present Stanislaus, but it was de- 

 stroyed by a lava flow, which left no place for the water, rose 

 to the level of the banks, and after they were washed away 

 by the water, rose up like a mountain, with a serpentine 

 course, steep sides, and a bare and level top. In sinking down 

 through the middle of Table Mountain, the miner passes 

 through 150 feet of basalt, 100 of volcanic sand, 50 of clay 

 and sand, 30 of gravel, (the lowest 10 feet being rich in gold) 

 and then strikes the bed-rock of slate. When that channel 

 was filled up, and became a dead river, the waters had to find 

 a new course in the live Stanislaus. 



266. Dead Blue fiiver.The greatest dead river of Cal- 

 ifornia in length, breadth, depth and wealth, is " The Dead 

 Blue River," as I call it. Some gentlemen, connected witli the 

 State Geological Survey, have denied the correctness of my 

 assertion, that there is such a stream ; and they claim that the 

 gravel deposits which I include in it, were not made in a river- 

 bed : but I adhere to my opinion. A line of placer mining 

 towns extends from Forest Hill, on the southern line of Placer 



