CONTENTS 



1. The Rio Grande Valley, by Edgar Lee Hewett 11 



2. Geology and Topography, by Junius Henderson 2;^ 



3. ('limate and Evidence of Climatic Changes, by Junius Henderson and 



Wilfred William Robbins 41 



Introduction 43 



Present climate 43 



Evidence of change of climate in other regions < 44 



Archeological and historical evidence of change of climate 47 



Botanical evidence of change of climate 56 



Geological evidence of change of climate 60 



Summary 68 



Suggestions for future work 69 



4. Bibliography 71 



