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SUPPLEMENTARY INVESTIGATIONS IN THE GRAVEL REGION 





channel on the divide between the South and Middle Yubas. This is strong evidence in favor of 

 the hypothesis that the old channels were once connected, and the hypothesis receives further 

 support from the existence of small bodies of gravel high up on the spurs of the western slope of 

 the Oregon Creek canon, below Camptonville. These smaller deposits I did not have time to 

 visit ; I was first told about them by Mr. Bray. 



For determining the grade of the old channel across the ridge I took barometric observations at 

 Camptonville, at Galena Hill, and at Depot Hill. Observations were also taken at Indian Hill, to 

 which reference will be made further on. The fall between Depot Hill and Camptonville, a dis- 

 tance of about four miles and a half, I make to be 463 feet, or 103 feet to the mile. The altitude 

 of bed-rock at Galena Hill is confirmatory of this result. 



The old gravel mines at Camptonville covered an area of about 2,000 feet in length by 1,000 

 feet in width. Bed-rock ridges rise both to the east and west, which effectually preclude any other 



supposition than that the old channel had a southerly direction. The bed-rock is nearly level for 

 the greater part of the width of the channel, rising rapidly as the rim is approached. The gravel 

 appears to have been mainly quartz, of a reddish or a yellowish color. The banks were about 

 ninety feet in height. The gold was fine and scaly. The richest portions are said to have been 

 on the western rim. 



The canon of Willow Creek separates Camptonville from Galena Hill. By the route I followed 

 between these places I was not able to trace in detail the probable course or connections of the old 

 channel. The Galena Hill gravel, like that at Camptonville, is hemmed in on the east and west 

 by high bed-rock, that on the west being on the opposite side of Horse Valley or Brandy Creek. 

 The tailings from the Galena Hill mines are discharged into Willow Creek. The longest axis 

 of the diggings has a course of N. 65° W. (magnetic), and is from 1,000 to 1,200 feet in 

 length. The width of the gravel I estimated at from 600 to 800 feet, and the highest banks 

 are from fifty to seventy feet in height. The gravel is of a red or yellow color, like that at Camp- 

 tonville. Upon the bed-rock I saw scarcely anything excepting pebbles of white quartz. There 

 was no one at work at Galena Hill at the time I was there, and the gravel appears to be nearly 

 all gone. 



Horse Valley Creek makes a shallow separation between Galena Hill and Young's Hill, the 

 limits of the gravel on the two sides of the creek being barely a quarter of a mile apart. I did not 

 make any personal inspection of the gravel at Young's Hill. I was told that the richest portions 

 lay on the eastern rim, instead of on the western rim, as at Camptonville. If this statement is to 

 be relied upon, its explanation is to be looked for in the curve that the old channel must have 



made near this point. 



At Weed's Point I estimated the thickness of the workable gravel to be 125 feet, the lower 

 twenty-five feet being blue in color, and the remainder red ; but I did not stop to make any 

 detailed examination of the bank. 



Eailroad Hill lies to some distance to the east of the road from Camptonville to Oak Valley, 

 and was never a deposit of much importance. I was told that it is entirely worked out, and 

 accordingly I did not think it worth while to make a special excursion to it. 



At Depot Hill there is one of the largest bodies of gravel which renin in to be worked in this 

 vicinity. It occupies the crest of the ridge, or the divide, between Willow Creek and Indian 

 Creek. It is worked both on the northern and the southern end, at the former discharging tail- 



ings into Indian Creek, and at the latter into Oak Valley Creek near its junction with Willow 

 Creek. The deposit is about half a mile in length, along a course S. 17° W. (magnetic). Its ex- 

 treme width at the northern end, where all my observations were made, is between five and six 

 hundred feet, four hundred feet being in deep gravel. It is evident that the old channel must 

 have crossed directly from Grizzly Hill (near Brandy City) or by way of Indian Hill. The Indian 

 Hill, Grizzly Hill, and a portion of the Brandy City gravels are all in sight from the north end of 

 Depot Hill, and are all enough higher than the latter to assure at least the average grade for the 

 old channel between them. Grizzly Hill bears ST. 15° W. (magnetic) from Depot Hill, while 



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