234 APPENDIX. 



In many localities the areas laid bare amount to hundreds 

 of acres in single tracts. 



In portions of Amador and Calaveras Counties, multitudes 

 of "prospects" join each other, extending for miles upon a 

 so-called " river-bar." 



These " prospects" are frequently only holes that have been 

 excavated from four to ten feet in depth, and the auriferous 

 gravel thrown out and scattered far enough to nearly com- 

 pletely cover the original surface soil for from one to ten inches. 



In Placer and Nevada Counties the process of hydraulic 

 mining has generally washed out vast flats or valleys in the 

 mountains, and leaving the resulting basin covered chiefly 

 with gravel, boulders, or blue clay. 



These operations have been discontinued in some localities 

 for now more than thirty years ; in others, only recently. 



Yet in all of them, and apparently with an utter dearth of 

 soil, the native timber is making an effort to assert itself. 



At Dutch Flat, where gigantic mining operations have only 

 ceased during three years, a very sparse setting of small 

 Psuedotsuga Douglasii, Pinus tuberculata, Libdocedrus decurrens, 

 and Pinus Sabinana have established themselves. The same 

 features exist upon the Mokelumne Kiver, in Calaveras County, 

 where no mechanical disturbance has occurred since the 

 original covering up of the soil thirty years before. 



Both localities are between three thousand and three thou- 

 sand six hundred feet in elevation, and the timber is such as 

 belongs to that elevation in the Sierras. 



The uninjured timber in the more southern county and 

 adjoining denuded lands, can only be described as scrubby; 

 and 1 cannot say that that which has established itself upon 



