﻿CHAPTER 
  IV. 
  

  

  THE 
  SAN 
  JUAN 
  EEGION. 
  

  

  The 
  area 
  treated 
  of 
  in 
  this 
  chapter 
  contains 
  the 
  drainage 
  of 
  Eio 
  San 
  

   Juan, 
  so 
  far 
  as 
  falling 
  within 
  the 
  limits 
  of 
  our 
  district. 
  The 
  river 
  itself 
  

   will 
  be 
  considered 
  from 
  its 
  headwaters 
  down 
  to 
  its 
  junction 
  with 
  Eio 
  

   Animas. 
  In 
  speaking 
  of 
  the 
  Sawatch 
  Eauge 
  in 
  the 
  previous 
  chapter, 
  a 
  

   number 
  of 
  streams 
  flowing 
  into 
  the 
  San 
  Juan 
  have 
  been 
  mentioned, 
  and 
  

   their 
  headwaters 
  discussed. 
  Besides 
  these, 
  however, 
  there 
  are 
  others 
  

   farther 
  west 
  that 
  belong 
  to 
  the 
  same 
  drainage. 
  During 
  1874 
  the 
  sources 
  

   of 
  these 
  were 
  examined 
  and 
  reported 
  on, 
  so 
  that 
  where 
  we 
  meet 
  them, 
  

   in 
  the 
  district 
  of 
  1875, 
  along 
  its 
  northern 
  boundary 
  they 
  are 
  good-sized 
  

   streams, 
  carrying 
  a 
  considerable 
  amount 
  of 
  water. 
  Lying 
  between 
  the 
  

   tributaries 
  of 
  the 
  San 
  Juan, 
  we 
  find 
  the 
  country 
  to 
  be 
  very 
  uniform 
  in 
  

   appearance. 
  Two 
  ''belts," 
  mainly, 
  may 
  be 
  observed, 
  the 
  one 
  at 
  the 
  

   immediate 
  base 
  of 
  the 
  mountains, 
  the 
  other 
  between 
  that 
  and 
  the 
  river. 
  

   South 
  of 
  the 
  river 
  the 
  country 
  becomes 
  monotonous, 
  both 
  in 
  its 
  oro- 
  

   graphic 
  features 
  and 
  its 
  geognostic 
  character. 
  As 
  wilt 
  be 
  seen 
  in 
  the 
  

   subsequent 
  pages, 
  the 
  recognition 
  of 
  geological 
  formations 
  in 
  this 
  south- 
  

   ern 
  portion 
  of 
  the 
  district 
  becomes 
  a 
  rather 
  complex 
  question. 
  

  

  DRAINAGE. 
  

  

  Beginning 
  in 
  the 
  west 
  with 
  the 
  streams 
  and 
  rivers 
  flowing 
  in 
  a 
  south- 
  

   erly 
  direction, 
  we 
  first 
  fihd 
  the 
  Animas. 
  This 
  heads 
  near 
  station 
  ]5 
  of 
  

   1874, 
  about 
  14 
  miles 
  above 
  Baker's 
  Park, 
  flows 
  from 
  the 
  station 
  through 
  

   a 
  narrow 
  volcanic 
  cauon, 
  then 
  enters 
  the 
  park. 
  There 
  it 
  receives 
  a 
  num- 
  

   ber 
  of 
  tributaries, 
  among 
  which 
  the 
  Cunningham 
  and 
  Mineral 
  Creeks 
  

   are 
  the 
  largest. 
  After 
  leaving 
  the 
  park 
  it 
  enters 
  the 
  narrow 
  quartzitic 
  

   canon, 
  known 
  as 
  the 
  Animas 
  Caiion, 
  and 
  emerges 
  from 
  that 
  south 
  of 
  

   station 
  38 
  of 
  1874. 
  Cascade 
  Creek 
  joins 
  it 
  from 
  the 
  northwest 
  at 
  that 
  

   point. 
  Flowing 
  for 
  some 
  distance 
  through 
  a 
  narrow 
  valley, 
  the 
  river 
  

   enters 
  the 
  Animas 
  Park, 
  at 
  the 
  lower 
  end 
  of 
  which 
  it 
  receives 
  the 
  

   waters 
  of 
  the 
  Eio 
  Arenoso. 
  By 
  that 
  time 
  we 
  have 
  arrived 
  in 
  Cretace- 
  

   ous 
  beds, 
  which 
  form 
  a 
  series 
  of 
  west 
  to 
  east 
  hogbacks 
  and 
  broken 
  

   ridges. 
  "Within 
  these. 
  Junction 
  Creek 
  flows 
  into 
  the 
  Animas 
  at 
  the 
  • 
  

   crossing 
  of 
  the 
  old 
  Ute 
  trail. 
  Below 
  that 
  the 
  district 
  of 
  1874 
  ends. 
  We 
  

   now 
  find 
  the 
  river 
  winding 
  a 
  serpentine 
  course 
  through 
  a 
  broad 
  valley, 
  

   hugging 
  at 
  times 
  the 
  bluffs 
  on 
  its 
  eastern 
  side. 
  At 
  station 
  51 
  it 
  forms 
  

   the 
  junction 
  with 
  the 
  Eio 
  Florida, 
  which, 
  rising 
  in 
  the 
  mountains 
  farther 
  

   north, 
  flows 
  in 
  a 
  southerly 
  direction, 
  until 
  near 
  station 
  50 
  it 
  takes 
  a 
  

   westerly 
  turn 
  and 
  joins 
  the 
  Animas. 
  Thus 
  far 
  the 
  general 
  course 
  of 
  

   this 
  river 
  has 
  been 
  nearly 
  due 
  south, 
  but 
  now 
  it 
  bends 
  off" 
  to 
  the 
  west- 
  

   ward, 
  and 
  forms 
  a 
  junction 
  with 
  the 
  San 
  Juan 
  about 
  10 
  miles 
  below 
  

   station 
  54. 
  Below 
  station 
  51 
  the 
  river 
  has 
  no 
  tributaries 
  that 
  carry 
  

   water 
  during 
  the 
  entire 
  year. 
  Only 
  a 
  few 
  of 
  them, 
  probably, 
  carry 
  

   water 
  during 
  the 
  early 
  spring 
  months 
  and 
  during 
  the 
  rainy 
  season. 
  

  

  176 
  

  

  