Vlll PREFACE. 



synopsis of the field-work of the Survey was given, up to the 

 close of the year 1863. In Geology Vol. I, a synopsis of the 

 operations of the Survey was given up to the date of Novem- 

 ber, 1865, which is that of the preface of the volume. For 

 the convenience of those who may possess the palseontological 

 volumes of the Report only, the resume of our work given in 

 Volume I of that series, will here be continued, in as concise 

 a manner as possible, up to the date of the suspension of the 

 field-work in 1867, the failure of the Legislature of 1867-68 

 to make an appropriation for the continuance of the Survey, 

 having compelled us to bring our active operations to a close. 

 The question of the resumption of the field-work is one to be 

 decided by a future Legislature. 



The party under the direction of Professor Brewer, men- 

 tioned in the Preface of the Palaeontology, Vol. I, as being in 

 the field at the time of its publication, and which commenced 

 operations in May, proceeded across the plains of the San 

 Joaquin to Visalia, from which point they entered the Sierra, 

 ascending King's River to its source, and exploring the whole 

 region about the headwaters of that and Kern River. Thence 

 they made their way across the range by a pass over 12,000 

 feet high; passed up Owen's Valley, ascended the west branch 

 of Owen's River, crossing the Sierra again at an altitude of 

 12,400 feet, and thence descending to the head of the San 

 Joaquin River. The exploration was continued through the 

 region of the headwaters of that stream and the Merced, con- 

 necting the reconnoissance with that of 1863 around the 

 sources of the Tuolumne. The whole expedition occupied 

 about three months, during which time the geography and 

 geology of a district including an area of over 10,000 square 

 miles were, for the first time, explored, the whole region 

 having previously been entirely unknown. The results 



