458 / HARLEN BRETZ 



Quercus venustula and Sequoia sempervirens in the collection. Both 

 are living species. 



Age of the Cascade Mountains. — If the foregoing determinations 

 are correct, the Cascade Range, at least in this portion, is of 

 Quaternary age. 



Acknowledgments. — -During the progress of the field work on 

 which this paper is based, nine weeks were spent with the Wash- 

 ington Geological Survey and four weeks with the Oregon Bureau 

 of Mines and Geology. I wish to acknowledge indebtedness to 

 both organizations, and in particular to Mr. Ira A. Williams, with 

 whom I was associated during the work for the Oregon Bureau. 



