368 PROCEEDINGS OF THE CALIFORNIA 



beds are on the Youkon, and they extend about sixty miles. They are brown 

 sandstones, containing bivalve mollusca and vegetable remains. There is a 

 small seam of coal thirty miles below the bend, and thin sha!e abore and below. 

 The coal is of good quality ; but there is so little of it that it is worthless. 

 These are the only fossiliferous strata I have thus far found. The rocks above 

 and below are all azoic and nonstratified, excepting a little hard blue or black 

 slate. Granite, and especially mica, are very rare. I found a pebble containing 

 the well known fossils of the Niagara limestone on the beach near Fort 

 Youkon. Fossil wood and bones and teeth of Elephas and (Jvibos moschalus 

 are common over the country. There is a broad patch of volcanic eruptive 

 rock on the river near the lower bend, and it extends to the sea. The islands 

 of St. Michael and Stuart are formed of it, and it is roughly columnar on the 

 former near the Fort." 



" I have looked carefully for glacial traces, and so far have found absolutely 

 none." 



Mr. Dall adds that it is his intention to spend another year in 

 Russian America, working at his own expense, in order to finish 

 the explorations commenced by himself, and which the failure of 

 the Telegraph Company rendered it impossible for him to continue 

 officially. 



Dr. Cooper and Professor Whitney discussed the question 

 whether the volcanoes of Oregon and Washington Territory were 

 to be classed as active. The evidence on this point seemed very 

 conflicting, so far as showers of ashes are concerned. There is no 

 doubt, however, of the existence of solfataric action on Mount 

 Hood, Mount St. Helens, and probably on Rainier and Baker. 



Professor Whitney exhibited some photographs and stereographs, 

 taken for the Geological Survey by Mr. W. Harris, in the Upper 

 Tuolumne Valley, near Soda Springs, Mount Dana, Mount Hoff- 

 mann, and Mount Lyell. He also presented the following account 

 of a remarkable portion of the Tuolumne Valley, which forms 

 almost an exact counterpart of the Yosemite. It is by Mr. Hoff- 

 mann, the head of a party of the Geological Survey, by which it 

 was explored last summer : 



Notes on Heteh-Hetehy Valley. 



BY C. P. HOFFMANN. 



Tuolumne Valley, or Hetch-Hetchy, as it is called by the Indians (the mean- 

 ing of this word I was unable to ascertain) is situated on Tuolumne River about 

 fifteen miles in a straight line below Tuolumne Meadows and Soda Springs, and 

 about twelve miles north of Yosemite Valley. Its elevation above the sea is 



