One autumn my entire time was spent in making observations and watching the activities of beaver in fourteen colonies. Sixty-four days in succession I visited these colonies, three of them twice daily. These daily investigations enabled me to see the preparations for winter from beginning to end. They also enabled me to understand details which with infrequent visits I could not have even discovered. During this autumn I saw two houses built and a number of old ones repaired and plastered. I also saw the digging of one canal, the repairing of a number of old dams, and the building of two new ones. In three of these colonies I tallied each day the additional number of trees cut for harvest. I saw many trees felled, and noted the manner in which they were moved by land and floated by water. The greater number of the papers in this book were written especially for it. Parts of the others have been used in my books _Wild Life on the Rockies_ and _The Spell of the Rockies_. "The Beaver's Engineering" appeared in the _Saturday Evening Post_, and I am indebted to _McClure's_ for permission to use "Beaver Pioneers." Beaver works are of economical and educational value besides adding a charm to the wilds. The beaver is a persistent practicer of conservation and should not perish from the hills and mountains of our land. Altogether the beaver has so many interesting ways, is so useful, skillful, practical, and picturesque that his life and his deeds deserve a larger place in literature and in our hearts. E. A. M. Contents Working like a Beaver 1 Our Friend the Beaver 17 The Beaver Past and Present 37 As Others See Him 51 The Beaver Dam 63 Harvest Time with Beavers 81 Transportation Facilities 99 The Primitive House 117 The Beaver's Engineering 137 The Ruined Colony 151 Beaver Pioneers 173 The Colony in Winter 195 The Original Conservationist 211 Bibliographical Note 223 Index 225 Illustrations