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  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1922. 
  

  

  As 
  there 
  is 
  evidence 
  that 
  the 
  beavers 
  themselves 
  have 
  at 
  times 
  

   been 
  responsible 
  for 
  the 
  flooding 
  of 
  the 
  big 
  slough, 
  and 
  they 
  have 
  

   actually 
  excavated 
  its 
  bottom 
  in 
  places 
  in 
  line 
  with 
  or 
  even 
  in 
  con- 
  

   tinuation 
  of 
  the 
  upper 
  and 
  lower 
  canals, 
  it 
  seems 
  only 
  just 
  to 
  reckon 
  

   the 
  entire 
  length 
  of 
  the 
  watercourse, 
  or 
  745 
  feet, 
  as 
  that 
  of 
  the 
  canal. 
  

   So 
  credited, 
  it 
  becomes 
  one 
  of 
  the 
  longest 
  which 
  has 
  been 
  recorded. 
  7 
  

  

  In 
  summary 
  then 
  it 
  may 
  be 
  said 
  that 
  the 
  canal 
  seems 
  to 
  occupy, 
  

   and 
  in 
  large 
  degree 
  to 
  have 
  taken 
  advantage 
  of 
  a 
  long 
  swale, 
  which 
  

   at 
  its 
  upper 
  end 
  bears 
  evidence 
  of 
  being 
  the 
  remnant 
  of 
  an 
  ancient 
  

   rivulet, 
  now 
  dry, 
  the 
  lower 
  portion 
  now 
  at 
  best 
  not 
  possessing 
  

   gradient 
  enough 
  or 
  running 
  water 
  enough 
  to 
  maintain 
  an 
  unbroken 
  

   outflow 
  into 
  the 
  river. 
  This 
  necessary 
  detail 
  was 
  accomplished 
  by 
  

   the 
  beavers, 
  who 
  have 
  pushed 
  their 
  canal 
  through 
  a 
  cut 
  in 
  the 
  

   vegetation-covered 
  bank 
  of 
  the 
  river, 
  and 
  thus 
  made 
  possible 
  the 
  

   full 
  development 
  of 
  the 
  entire 
  system. 
  

  

  The 
  canal 
  has 
  now 
  been 
  under 
  observation 
  as 
  opportunity 
  has 
  pre- 
  

   sented 
  for 
  six 
  summers, 
  and 
  I 
  have 
  also 
  been 
  able 
  to 
  pay 
  it 
  a 
  winter 
  

   visit 
  or 
  two. 
  As 
  lias 
  been 
  related, 
  the 
  canal 
  was 
  in 
  its 
  highest 
  state 
  of 
  

   perfection 
  in 
  July 
  and 
  August 
  of 
  1916. 
  A 
  year 
  later 
  it 
  had 
  been 
  some- 
  

   what 
  damaged 
  by 
  the 
  abnormally 
  high 
  water 
  of 
  that 
  season, 
  and 
  

   although 
  it 
  continued 
  to 
  be 
  occupied 
  it 
  was 
  never 
  fully 
  restored. 
  In 
  

   July 
  of 
  1918 
  I 
  found 
  it 
  very 
  miry 
  and 
  in 
  bad 
  shape 
  in 
  other 
  par- 
  

   ticulars, 
  but 
  the 
  beavers 
  were 
  still 
  actively 
  utilizing 
  it 
  and 
  did 
  a 
  little 
  

   work 
  on 
  it 
  during 
  the 
  rest 
  of 
  that 
  summer. 
  A 
  miserably 
  cruel 
  and 
  

   needless 
  onslaught 
  carried 
  on 
  against 
  them 
  by 
  persons 
  who 
  chanced 
  

   to 
  be 
  temporarily 
  connected 
  with 
  the 
  operations 
  of 
  the 
  ranch 
  along 
  

   about 
  this 
  time 
  so 
  depleted 
  their 
  numbers 
  that 
  until 
  quite 
  recently 
  it 
  

   was 
  feared 
  it 
  would 
  be 
  many 
  years 
  before 
  the 
  damage 
  could 
  be 
  made 
  

   good. 
  Certainly 
  the 
  canal 
  showed 
  the 
  effect 
  of 
  this 
  slaughter, 
  for 
  in 
  

   1919, 
  which 
  was 
  a 
  year 
  of 
  almost 
  unprecedented 
  drought 
  and 
  low 
  

   water, 
  when 
  they 
  would 
  normally 
  have 
  been 
  exceedingly 
  assiduous 
  in 
  

   storing 
  back 
  as 
  great 
  a 
  proportion 
  of 
  the 
  retreating 
  waters 
  as 
  pos- 
  

   sible, 
  the 
  entire 
  canal 
  was 
  absolutely 
  dry, 
  pond 
  and 
  all, 
  and 
  badly 
  

  

  7 
  Seton 
  (Life 
  Histories 
  of 
  Northern 
  Animals, 
  vol. 
  1, 
  p. 
  458) 
  records 
  a 
  beaver 
  canal 
  at 
  

   Gal 
  Pond, 
  in 
  the 
  Adirondacks, 
  654 
  feet 
  long 
  and 
  some 
  4 
  feet 
  wide, 
  leading 
  " 
  from 
  the 
  

   pond 
  to 
  a 
  grove 
  of 
  poplar 
  and 
  yellow 
  birch." 
  "Although 
  abandoned 
  for 
  fully 
  50 
  years, 
  

   it 
  was 
  very 
  well 
  marked 
  and 
  showed 
  many 
  beaver 
  cuttings." 
  Most 
  of 
  Seton's 
  discussion 
  

   of 
  beaver 
  canals 
  is, 
  however, 
  taken 
  from 
  Morgan. 
  . 
  

  

  Mills 
  (In 
  Beaver 
  World, 
  p. 
  140—141) 
  describes 
  and 
  illustrates 
  a 
  remarkable 
  canal 
  near 
  

   Long's 
  Peak, 
  Colo., 
  which 
  was 
  excavated 
  through 
  a 
  deep 
  wreckage 
  of 
  fire-killed 
  and 
  fallen 
  

   spruces 
  in 
  order 
  to 
  permit 
  the 
  successful 
  harvest 
  of 
  a 
  certain 
  grove 
  of 
  aspens. 
  This 
  canal 
  

   was 
  334 
  feet 
  long, 
  with 
  an 
  average 
  depth 
  of 
  15 
  inches 
  and 
  a 
  width 
  of 
  26 
  inches. 
  Still 
  

   more 
  noteworthy 
  is 
  the 
  very 
  complex 
  canal 
  which 
  he 
  observed 
  near 
  Three 
  Forks, 
  Mont, 
  

   (op. 
  cit., 
  p. 
  107-111, 
  fig.), 
  and 
  which 
  had 
  a 
  total 
  length 
  of 
  428 
  feet. 
  

  

  By 
  far 
  the 
  longest 
  canal 
  recorded 
  by 
  this 
  author 
  was 
  observed 
  at 
  Lily 
  Lake, 
  Colo, 
  

   (op. 
  cit., 
  p. 
  104, 
  ill. 
  opp. 
  p. 
  102). 
  This 
  canal 
  was 
  one 
  of 
  a 
  number 
  built 
  by 
  the 
  beavers 
  

   of 
  the 
  local 
  colony 
  in 
  order 
  to 
  maintain 
  necessary 
  water 
  thoroughfares 
  in 
  the 
  bed 
  of 
  their 
  

   home 
  lake 
  during 
  a 
  time 
  of 
  drought. 
  It 
  was 
  measured 
  to 
  be 
  750 
  feet 
  long, 
  3 
  feet 
  deep 
  

   throughout, 
  and 
  from 
  3 
  to 
  5 
  feet 
  wide. 
  

  

  