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University of California. 



[Vol. :i. 



a broad cove extending into the hills, and it is floored chiefly 

 by a broad, low alluvial fan of a tributary stream, the outer 

 edge of which merges into the forty-five-foot terrace. By 

 reason of erosion the bank near the river is of unequal height. 

 Just below the Ferris Mine there is a small flat at about thirty 

 feet above the river, and this is siieceeded by a flat rising to 

 about sixty or seventy feet above the river. Its steep outer 

 slope shows horizontally stratified fine gravel of a gray color 

 and a local slate composition. It declines rapidly downstream 

 until it merges into a flat whose height is forty feet above 

 low-water mark. The steep bank facing the river displays 

 brown sand and silt in horizontal layers, with very little gravel. 

 The flat is cultivated as the lower farm of the Orleans Bar 

 Gold Mining Company, and consequently is above high-water 

 mark. 



Opposite this farm the river makes a great bend to the south 

 around Graham Bar, about thirty-four and one-third acres 

 in extent, which at high water is an island cut off from 

 the mainland by a channel 300 feet wide and 700 feet 

 long, leading to Camp Creek. The bar has a maximum 

 height of forty-five feet above the river. Bed-rock is 

 exposed near the river on two sides, but does not rise high. 

 The surface of the bar is very bouldery except a patch at the 

 west end, where the soil is a dark brown sand, as at Sandy Bar. 

 This portion of the bar is slightly higher than the bouldery 

 portion, and the latter, it seems evident, has had the sandy layers 

 removed by the river at high water. On the west side of the bar, at 

 the mouth of Camp Creek, there is a narrow strip representing 

 a terrace twelve feet lower than the forty-five-foot terrace, and 

 corresponding to a terrace on the opposite side of Camp Creek, 

 occupied by the Salstrom farm. This lower terrace" consists of 

 fine material (mainly sand), and may be considered local to 

 the Camp Creek system, although there are traces of a similar 

 level at many places along the river. 



In the Lower Basin, the forty-five foot terrace has been 

 mined from the mouth of Boise Creek to one-fourth of a mile 

 up the river, and probably eight acres removed. The river 

 floods the mine at extreme high water and has buried the bed- 



