136 



Sierra Club Bulletin 



STUDYING THE YOSEMITE PROBLEM* 



By F. E. Matthes, United States Geological Survey 



Some of the readers of this magazine, upon learning that 

 the geology of the Yosemite region has been given a careful 

 investigation by a party of government scientists during the 

 past summer, will probably exclaim : "What, again ? Has not 

 the Yosemite region been studied by geologists several times 

 before, and do we not know all there is to know about it by 

 this time?" 



Indeed, we do not know all there is to know about it. Last 

 summer's investigations have revealed — if nothing else — how 

 imperfect still is our understanding of the much-admired 

 Yosemite Valley and how great the difficulty of penetrating 

 deeper into its mysteries. The Yosemite problem has been 

 studied more than once in the past ; it is being studied now, 

 and it undoubtedly will bear further study in the future. 



But in the meanwhile headway is constantly being made to- 

 wards its solution. Each new investigator comes to the task 

 better prepared than his predecessors — better prepared because 

 in the possession of the cumulated knowledge, so to speak, of 

 those who went before, and, in addition, of that advanced 

 knowledge that is his by virtue of the general progress made 

 by science. All these advantages last year's party enjoyed 

 also, but besides, there was a feature of its equipment that 

 seemed to give it special promise of success, namely the pos- 

 session of an accurate large-scale map of the Yosemite region. 



The unraveling of a complex problem such as that of the 

 Yosemite Valley naturally demands the very detailed, con- 

 centrated study of certain localities, and work of that sort 

 cannot well be executed without the aid of a topographic map 

 of commensurate detailedness. Until a few years ago, when 

 the United States Geological Survey published its "Map of the 

 Yosemite Valley" on a special scale of 2,000 feet to the inch 

 (a scale about five times as large as that used for the map- 

 ping of most of the Sierra country), such cartographic ma- 

 terial was not available. In general it may be said that what 



•Published with permission of the Director of the U. S. Geological Survey. 



