PREFACE. Xlll 



ing completed this task, it had been my intention to have 

 the party cross the San Joaquin River, and meet me at Snel- 

 ling's, on the Merced, and then to devote the remainder of 

 the season to working up the geology of the foot-hills of the 

 Sierra Nevada, going as far north as time would permit, and 

 then returning on the west side of the Sacramento, along 

 the foot-hills of the Coast ranges north of the Bay of San 

 Francisco. It appeared, however, that all the ferries of the 

 San Joaquin had been broken up by the unprecedented storms 

 of the previous winter (1861-2), so that there was no possi- 

 bility of crossing at any point, the river continuing greatly 

 swollen by the melting of the snow of the Sierra until late 

 in the season. This rendered a change in our plans neces- 

 sary, as the party had to return up the San Jose Valley arid 

 cross at Benicia. It was then determined to continue the 

 work up the valley, along the Coast ranges west of the 

 Sacramento River, with the view of reaching Mount Shasta 

 before it would be too late in the season for its ascent. This 

 plan was partially carried out, and the region north of Beni- 

 cia explored as far as Rag Canon ; but the severe sickness of 

 several of the party during the summer, seriously interfered 

 with our progress. After reaching and ascending Mount 

 Shasta, additional explorations were made in that vicinity, 

 in Shasta, Siskiyou, and Trinity counties, and afterwards 

 along the east side of the Sacramento Valley, in the foot- 

 hills, for the purpose of ascertaining more clearly the rela- 

 tions of the Cretaceous formation to the auriferous slates of 

 the Sierra Nevada. Still later in the season, the field-work 

 being continued to the end of November, the vicinity of the 



