THE WASHINGTON RIDGE. 



411 



average height of bank at the time those " claims " were worked, the yield per cubic yard was 

 about 13J cents. 



There being some uncertainty about the area covered by the gravel between Omega and Diamond 

 Creek, I thought it necessary to extend my examination in that direction. In so doing I followed 

 first the line of the Omega ditch to a point opposite the Diamond Creek diggings, and subsequently, 

 for a part of the way, the Blue Tent ditch, which runs nearly parallel to the other but at a, higher 

 altitude. The difference of altitude between the two ditches at a point near Omega I made to be 



170 feet. On the Omega ditch I first saw bed-rock near the head of Iowa Ravine. Its altitude 

 was about forty feet higher than the highest surface of the gravel at Omega. For the rest of the 

 distance as far as Diamond Creek I saw in the ditch nothing but slate, or some other variety of 

 schistose bed-rock. Upon the top of the ridge between Iowa Ravine and Missouri Canon, 

 near where the ditch is carried through a short tunnel, there was a small deposit of rolled gravel 

 which very likely was once connected with the high bench at Cold Flat. There had been an 

 opening made of perhaps 300 feet in diameter and fifteen in depth. The Blue Tent ditch was in 

 lava until after the crossing of the spur between Iowa Ravine and Missouri Canon, and from that 

 point on in slate as far as the second or third branch of Diamond Creek, which was the limit of 

 my walk in that direction. I went for enough to satisfy myself that the quartz gravel, said to be 

 seen in the Blue Tent ditch above Missouri Canon, had no obvious connection with the deposit at 

 Omega. 



The gravel at Diamond Creek extends for half a mile or more, principally upon the right or 

 eastern bank of the creek, and about one hundred and fifty feet above its present bed. I took one 

 observation for altitude upon the bed-rock near the old blacksmith-shop, just above the mouth of a 

 tunnel. I made the altitude at this point to be 4,206 feet. I saw no one at work. The bed-rock 

 has a steep pitch down the creek, and also a more gradual inclination under the bank of gravel 

 lying to the east. At one of the lower banks, farther down the stream, the top of the gravel was 

 on a level with my point of observation. Back of the gravel, bed-rock hills rise rapidly to a con- 

 siderable height. The gravel differs very much in appearance from that at Omega. It looks more 

 like an irregularly stratified drift, with small boulders distributed from top to bottom through a 

 reddish sandy gravel. Many of the boulders were evidently of volcanic origin, though not all At 

 one of the lower banks, as seen from across the creek, the gravel appeared to be finer and lighter- 

 colored. 



Taking all these facts into consideration, I was led to the conclusion that the gravel at this 

 point represents some former channel of Diamond Creek alone, and that there never was any 

 direct connection with the Omega deposit. 



From Omega I went by stage to a point about a mile below the Central House, and thence 

 on foot to Blue Tent and Sailor Flat ; but before reporting upon this portion of the ridge I will 

 add a few words about a small deposit of low gravel, winch probably owes its origin to the 

 washing away of the old channel between Alpha and Omega. 



The Hathaway claim, on the south bank of the South Yuba, at the mouth of Scotchman's 

 Creek, about a, mile above Washington, presents one or two features of interest. There is no 

 precisely similar deposit that I have heard of along the river, either above or below. The gravel 

 is reputed to extend back from the river for at least a quarter of a mile. Near the Yuba it 

 has a thickness of twenty-five feet, the lower half being blue in color while the top is red. 

 Farther from the river the thickness is considerablv greater, a bank of two hundred feet beins^ 

 looked for in some parts of the claim. This deposit has been prospected by means of tunnels 

 from the Yuba and from Scotchman's Creek, each about 1,200 feet in length. The mouth of 

 the latter tunnel is now buried seventy feet beneath failings. It seems almost beyond ques- 

 tion that this deposit came from the washing away by natural causes of a portion of the old 

 channel between Alpha and Omega, and it is probable that it has been caught where it is in 

 consequence of a change in the courses of the ravines, for there is sonic- evidence that there 

 "was formerly a different outlet, a little lower down the Yuba, for Krumbacher Ravine, or Scotch- 



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