(preface 



book is the result of beaver studies which 

 cover a period of twenty-seven years. During 

 these years I have rambled through every State 

 in the Union and visited Mexico, Canada, and 

 Alaska. In the course of these rambles notice 

 was taken of trees, birds, flowers, glaciers, and 

 bears, and studious attention devoted to the 

 beaver. No opportunity for beaver study was 

 missed, and many a long journey was made for 

 the purpose of investigating the conditions in live 

 colonies or in making measurements in the ruins 

 of old ones. These investigations were made dur- 

 ing every season of the year, and often a week 

 was spent in one colony. I have seen beaver at 

 work scores of times, and on a few occasions 

 dozens at one time. 



Beaver have been my neighbors since I was a 

 boy. At any time during the past twenty-five 

 years I could go from my cabin on the slope of 

 Long's Peak, Colorado, to a number of colonies 



vii 



