BEAVER DAMS. 121 



but in some places it is two and a hnlf and three feet 

 high, and constructed of stick- work on the lower, and 

 with an earth embankment on its water face. In 

 effect, therefore, it is one structure fifteen hundred 

 and thirty feet in length, of which five hundred and 

 thirty feet, in two sections, is artificial, and the re- 

 mainder natural bank, but worked here and there, 

 where depressions in the ground required raising by 

 artificial means. As this dam had been cut through, 

 and the water drawn out of the pond about two years 

 before I visited and measured the work in 1866, it 

 was then falling into decay. 



Three miles north of Clarksburg, in the south- 

 east quarter of section 25, there are three large 

 beaver dams, constructed on the same stream, and 

 from a quarter to a third of a mile apart. They are 

 situated upon an affluent of the main branch of the 

 Esconauba River. The first or lower dam measured 

 three hundred and eighty-five feet in length, and is a 

 large structure throughout its entire extent. It was 

 four feet high where it crossed the channel of the 

 stream, and three feet high for two-thirds of the re- 

 mainder of its length. Along this stream the prevail- 

 ing trees are spruce, tamarack, and cedar, interspersed 

 with poplar, with the latter of which the dam was 

 constructed. As the poplar is a soft wood, larger, 

 and often shorter billets were used, than in the dams 

 previously described. This dam, in external appear- 

 ance, was much inferior to those made of hard wood. 

 The upper dam measured five hundred and fifty-one 

 feet in continuous length along its crest. Divided into 

 sections it gave the following vertical elevations : 



