UPPER COURSE OF THE ANCIENT RIVER. 287 



How north of the North fork of Webber creek, but that any large and 

 important channel will ever be found on that .side is very unlikely. 

 except possibly at one point somewhat north of the section where a 

 tributary from the north appears to join the principal river by way of 

 Badger hill and Mooneys diggings (not indicated on the map). 



The lower part at least of this large and important channel may not 

 unlikely be found to pay for drifting; it can only be opened up by 

 means of tunnels from near Snows ranch or from some places along the 

 North fork of Webber creek. Inclines along the rim will probably suffer 

 from a heavy influx of water. 



At Pacific house the indications of an inlet are distinct, but I do not 

 think that much gold was ever found in the adjoining gulches. Oppo- 

 site that place, on a bench overlooking the South fork of the American 

 river, a small isolated area of gravel has been washed away by the 

 hydraulic process, and it is quite certain that the old channel crossed 

 the river at this point. More indications of the same channel are found 

 on the north side, a few miles eastward. Its course has not been traced 

 further, but it appears probable that it will be found to cross the river 

 again higher up, and that it headed up toward the Neocene volcanoes on 

 the line between Eldorado and Alpine counties. The channel is not 

 likely to be auriferous above the Pacific house. 



A broad belt of Neocene highlands with lofty peaks and ridges occu- 

 pied the space between the upper courses of the North and South forks 

 of the American river, and on the Georgetown divide a spur extended 

 from these highlands far toward the west. 



Grade : 

 Newtown to Pacific house, 10 miles, 100 feet to the mile. 



THE NORTH FORK. 



From the Junction to .Tone* Hill, — The lower course of the North fork of 

 the American river is almost completely destroyed by erosion ; its proba- 

 ble course from the valley up to the junction has already been mentioned. 

 Between the Lee mine and the Forest Hill divide there is only one re- 

 maining fragment, which, moreover, probably does not represent the 

 very deepest part of the channel, namely, the small patch of mixed 

 andesitic, rhyolitic, and metamorphic gravel found on top of the bluff at 

 the junction of the present North and Middle forks, about three miles 

 northwest of Auburn ; the presence of rhyolite in this gravel is a strong 

 proof that it came from the vicinity of Forest hill. This gravel is found 

 in the center of a very broad, low depression bordered on the north by 

 the Neocene highlands of ('Upper Gap and on the south by the rising 



