﻿BEAVER 
  CANAL 
  — 
  BERRY. 
  303 
  

  

  in 
  river 
  and 
  slough. 
  But 
  in 
  practice 
  the 
  problem 
  failed 
  to 
  resolve 
  

   itself 
  so 
  simply, 
  and 
  I 
  have 
  sometimes 
  been 
  quite 
  at 
  a 
  loss 
  to 
  explain 
  

   a 
  given 
  reversal 
  in 
  the 
  direction 
  of 
  flow. 
  With 
  the 
  river 
  at 
  fair 
  

   flood 
  I 
  have 
  found 
  the 
  entire 
  beaver 
  works 
  nearly 
  empty, 
  while 
  the 
  

   last 
  time 
  I 
  saw 
  the 
  canal 
  with 
  any 
  head 
  of 
  water 
  it 
  was 
  setting 
  

   distinctly 
  in 
  the 
  direction 
  of 
  the 
  slough 
  although 
  it 
  was 
  the 
  last 
  of 
  

   August 
  and 
  the 
  Musselshell 
  was 
  in 
  its 
  season 
  of 
  low 
  ebb. 
  It 
  is 
  

   possible 
  that 
  the 
  condition 
  of 
  the 
  big 
  slough 
  is 
  a 
  more 
  important 
  

   consideration 
  for 
  the 
  behavior 
  of 
  the 
  water 
  in 
  the 
  lower 
  canal 
  than 
  

   that 
  of 
  the 
  river. 
  When 
  the 
  Musselshell 
  is 
  very 
  low 
  the 
  river 
  end 
  

   of 
  the 
  canal 
  is 
  necessarily 
  high 
  and 
  dry, 
  and 
  at 
  such 
  a 
  season 
  the 
  

   slough 
  also 
  is 
  apt 
  to 
  be 
  reduced 
  to 
  a 
  mere 
  quagmire. 
  Measure- 
  

   ments 
  taken 
  in 
  the 
  latter 
  part 
  of 
  the 
  month 
  of 
  August, 
  1918, 
  showed 
  

   that 
  near 
  the 
  main 
  bend 
  (x 
  — 
  x 
  in 
  the 
  accompanying 
  diagram) 
  

   the 
  canal 
  had 
  a 
  low-water 
  diameter 
  of 
  5 
  feet, 
  or 
  of 
  9 
  feet 
  6 
  inches 
  

   measured 
  across 
  the 
  summits 
  of 
  the 
  levees 
  at 
  the 
  same 
  point. 
  At 
  

   the 
  mouth 
  it 
  was 
  9 
  feet 
  in 
  diameter 
  (8 
  feet 
  at 
  water 
  level), 
  with 
  

   a 
  maximum 
  depth 
  of 
  1 
  foot 
  8 
  inches 
  and 
  a 
  low-water 
  depth 
  of 
  

   10 
  inches. 
  Where 
  it 
  cut 
  through 
  the 
  willow 
  bank 
  (y 
  — 
  y 
  of 
  dia- 
  

   gram) 
  the 
  canal 
  diameter 
  at 
  high-water 
  level 
  was 
  6 
  feet 
  9 
  inches; 
  

   at 
  low-water 
  level 
  5 
  feet 
  6 
  inches. 
  The 
  low-water 
  depth 
  at 
  

   this 
  point 
  was 
  1 
  foot 
  to 
  1 
  foot 
  3 
  inches. 
  The 
  river 
  near 
  the 
  mouth 
  

   of 
  the 
  canal 
  was 
  about 
  50 
  feet 
  wide 
  at 
  this 
  time. 
  At 
  the 
  date 
  of 
  

   these 
  measurements 
  the 
  leveed 
  part 
  of 
  the 
  canal 
  had 
  already 
  begun 
  

   to 
  deteriorate 
  badly. 
  The 
  banks 
  were 
  partially 
  worn 
  down 
  (pi. 
  1, 
  

   and 
  pi. 
  3, 
  fig. 
  1) 
  and 
  the 
  hollows 
  in 
  the 
  swale 
  largely 
  filled 
  in 
  by 
  

   the 
  washings, 
  b;;' 
  ... 
  ,*ie 
  places, 
  especially 
  on 
  the 
  lower 
  or 
  east 
  

  

  side, 
  the 
  banks 
  remained 
  to 
  some 
  extent 
  leveed 
  above 
  the 
  adjoining 
  

   ground. 
  It 
  would 
  appear 
  that 
  in 
  its 
  pristine 
  condition, 
  upon 
  emerg- 
  

   ing 
  from 
  the 
  willow-clad 
  ridge, 
  the 
  canal 
  opened 
  directly 
  into 
  the 
  

   river 
  very 
  nearly 
  at 
  right 
  angles 
  with 
  the 
  shore 
  line, 
  or 
  even 
  deflected 
  

   to 
  head 
  a 
  trifle 
  upstream. 
  But 
  a 
  heavy 
  mud 
  bank 
  was 
  later 
  silted 
  

   across 
  it 
  by 
  the 
  river 
  current 
  so 
  persistently 
  that 
  after 
  a 
  little 
  effort 
  

   to 
  keep 
  open 
  an 
  adequate 
  passage 
  across 
  it, 
  the 
  beavers 
  capitulated 
  

   and 
  sheared 
  away 
  the 
  shore 
  , 
  ...o 
  east 
  a 
  little 
  in 
  such 
  a 
  way 
  as 
  to 
  

   run 
  their 
  channel 
  downstream 
  back 
  of 
  the 
  bar, 
  across 
  the 
  foot 
  of 
  

   which 
  it 
  then 
  opened 
  obliquely 
  into 
  the 
  river 
  without 
  much 
  danger 
  

   of 
  further 
  blocking 
  (pi. 
  4, 
  fig. 
  2). 
  Up 
  to 
  this 
  time 
  there 
  were 
  no 
  

   dams 
  of 
  the 
  beavers' 
  own 
  making 
  either 
  at 
  the 
  river 
  opening 
  of 
  the 
  

   canal 
  or 
  at 
  its 
  juncture 
  with 
  the 
  flooded 
  slough, 
  or, 
  in 
  fact, 
  at 
  any 
  

   point 
  between. 
  

  

  In 
  1918, 
  and 
  at 
  certain 
  times 
  previously, 
  the 
  slough 
  (pi. 
  3, 
  fig. 
  2) 
  at 
  

   the 
  head 
  of 
  the 
  leveed 
  canal 
  was 
  a 
  turbid 
  lake 
  some 
  260 
  feet 
  long 
  and 
  

   40 
  feet 
  across, 
  bordered, 
  like 
  the 
  swale 
  at 
  its 
  foot, 
  by 
  a 
  thick 
  growth 
  of 
  

  

  