300 RESOURCES OF CALIFORNIA. 



Bar, and Pine Log. The first four are within a circle with a 

 radius of five miles, a district which has been extremely rich 

 in placer diggings, and especially in large nuggets. In 1850 

 two lumps of twenty-three pounds, one each of eighteen, thir- 

 teen, ten, five, four, and three pounds, were found; in 1851 

 one each of twenty-eight, twenty-four, twenty-three, and five 

 pounds; in 1852 one each of nine and five pounds ; in 1853 

 one each of tAventy, ten, nine, eight, seven, and six pounds ; in 

 1854 one each of seventy-two, twenty-seven, sixteen, and seven- 

 teen pounds; in 1855 one of thirty pounds ; and in 1858 one 

 of thirty-three pounds. Two of the largest mining ditches in 

 the state supply water to the miners in the vicinity of Sonora 

 and Columbia. The number of mining ditches in the county 

 is twenty-one, and their aggregate length two hundred and 

 seventy miles. There are thirty quartz-mills, of which four are 

 at Quartz Hill, four at Tuttletown, three on the banks of the 

 Tuolumne River, and as many on Turnback Creek, at Colum- 

 bia, Soulsby's Ranch, and Wood's Creek two each, and at Bald 

 mountain. Big Oak Flat, Italian Camj), Jackson Flat, Moc- 

 casin Creek, Rawhide Ranch, Sonora, Whiskey Hill, Wood's 

 Crossing, and Yankee Hill, one each. The table-mountain in 

 Tuolumne county is the most remarkable elevation of its kind 

 in the state. It has an average height of five hundred feet, an 

 average width of four hundred yards, a length of thirty miles, 

 and a surface almost perfectly flat, slightly descending toward 

 the west. It was evidently formed by an immense stream of 

 lava, which was once confined between banks higher than its 

 own surface, which banks have since been washed away, leav- 

 ing the stream of lava standing like a mountain above the level 

 of the adjacent country. The sides near the top are perpen- 

 dicular and of solid basalt ; fiirther down they are sloping, and 

 composed of dirt and fragments of basalt that have fallen from 

 above. Under the basalt lie the gravel and sand of the ancient 

 river-bed, enclosed at the sides by ridges of rock, which rise 

 above the level of the adjacent plain. When therefore the min- 

 ers first wished to reach the auriferous deposits under the moun- 



