ANTICLINAL MOUNTAIN RIDGES IN CENTRAL 

 WASHINGTON/ 



The recent revival of interest in the Basin range type of 

 mountain structure has caused the review of many of the data 

 bearing upon that subject. Mountain ridges of the same type 

 were early described by Professor I. C. Russell' as occurring 

 over an area somewhat removed from the Great Basin. Similar- 

 ity of climate and the consequent presence of desert conditions 

 east of the Cascade mountains produce a certain resemblance of 

 central Washington to that region farther south, and the great 

 expanse of basalt lava also renders it natural to consider this 

 area as in a way the continuation of the northern portion of 

 the Great Basin. More questionable, however, is the assump- 

 tion that the type of mountain uplift commonly believed to 

 be so persistent in the Great Basin is likewise characteristic of 

 central Washington. 



A critical consideration of the earlier descriptions of the 

 structural features of central Washington is deemed essential at 

 the present time for two reasons. In the first place, the pub- 

 lished results of the geologic reconnoissances, containing as 

 they do the first descriptions of the area, possess the authority 

 that naturally goes with priority. Thus these statements of geo- 

 logic observation and inference come to be generally accepted 

 and cited by writers who have occasion to refer to the region; 3 

 and this general acceptance prevails, although quite different 

 descriptions of the area have been published which are based 

 upon later geologic studies of the same area.* It is therefore 

 desirable to state distinctly the opposition of later field observa- 

 tions to the statements based upon earlier work. This direct 



' Published by permission of the Director of the U. S. Geological Survey. 



^" A Geological Reconnoissance in Central Washington," Bull. U. S. Geol. Surv., 

 No. io8, 1893. 



3 An example of this can be found in the Third Report, Bureau of Soils, \]. S. 

 Dept. of Agriculture, p. 392, 1902. 



■* Water Supply and Irrigation Paper, U. S. Geol. Surv., No. 55, pp. 23, 24, 1901. 



166 



