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WARREN 



surveying the ground and finding out the levels and grades, had 

 to work it out on the ground by actual construction. Some 

 other things that I have known them to do have given me the 

 impression that they do work that way sometimes — the short 

 dam across the overflow around the end of the second dam, for 

 instance. 



The third house is a very large one, 17 by 22 feet on the 

 ground, of an oval shape, as the photograph shows (pi. xxix, 

 fig. 2) and 12 feet along the ridge on top. It is the largest 

 house I have ever seen. 



The construction of the 2 large dams across the stream, and 

 also of the various small ones, is practically the same. All are 

 built of willow stems and branches and mud, no large trees 

 being used, for none was to be had. They are substantially 

 constructed and the long ones are nearly 3 feet wide on top. 

 Farther up the river are dams in which the beaver used spruce 

 sticks, brought down the mountain sides by snow slides and left 

 where they would float down the river when the snow melted. 

 Some of the sticks so used are 4 or 5 inches through. But in 

 the dams I am now describing there is nothing of that kind. 

 The builders depended entirely on the willows, the largest of 

 which would hardly exceed an inch in diameter. But they so 

 mat and weave willows together — if the latter expression be 

 allowable, though not to be taken absolutely literally — and mix 

 and plaster them so thoroughly with mud that they are very 

 solid. The construction of a similar dam is shown in the 

 picture of an old dam which was cut through in order to drain 

 the pond (PI. xxxii, fig. 2). Nearly opposite the large house is 

 part of an old dam extending half way across the stream (PI. 

 xxvi). This is quite a massive structure; how old, I do not 

 know. 



Above this dam, as far as the limits of my survey, there are 

 occasional bunches of brush in the deep holes, also many sticks 

 with the bark peeled off, showing that the beavers were scattered 

 all along. As the banks are somewhat higher there was 

 opportunity for burrowing. At a number of places I also noted 

 the animals' slides and landing places. Across the Baxter and 

 Davis ditch, a small irrigating ditch 3 or 4 feet wide, beavers 



