﻿338 
  EEPOET 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  Professor 
  Newberry, 
  west 
  of 
  the 
  succession 
  of 
  parallel 
  ridges 
  just 
  men- 
  

   tioned. 
  After 
  a 
  lew 
  miles 
  of 
  this 
  course 
  it 
  leaves 
  the 
  plateau, 
  soon 
  

   turns 
  to 
  the 
  east, 
  and 
  flows 
  across 
  these 
  ridges 
  to 
  its 
  junction 
  with 
  the 
  

   San 
  Miguel, 
  whence 
  it 
  i)ursues 
  a 
  north-northwest 
  course 
  to 
  its 
  junction 
  

   with 
  the 
  Grand. 
  

  

  The 
  southwestern 
  part 
  of 
  the 
  district 
  is 
  occupied 
  by 
  the 
  Great 
  Sage- 
  

   plaiu, 
  which 
  is 
  drained 
  toward 
  the 
  southwestward 
  by 
  the 
  Montezuma, 
  

   a 
  dry 
  affluent 
  of 
  the 
  Rio 
  San 
  Juan. 
  

  

  The 
  heights 
  which 
  are 
  distributed 
  through 
  the 
  following 
  pages 
  were 
  

   determined 
  by 
  the 
  usual 
  methods 
  followed 
  by 
  the 
  survey, 
  by 
  mercurial 
  

   barometer, 
  aneroid, 
  and 
  vertical 
  angles. 
  The 
  barometric 
  observations 
  

   were 
  referred 
  as 
  follows 
  : 
  My 
  temporary 
  bases 
  in 
  1875, 
  on 
  the 
  Gunnison 
  

   and 
  Dolores, 
  we 
  computed 
  from 
  the 
  base 
  observations 
  at 
  White 
  Eiver 
  

   agency. 
  To 
  these 
  were 
  referred 
  all 
  observations 
  at 
  camps. 
  The 
  latter 
  

   being 
  established, 
  all 
  observations 
  on 
  stations 
  and 
  other 
  points 
  were 
  

   referred 
  to 
  them 
  ; 
  or, 
  in 
  cases 
  where 
  the 
  observations 
  would 
  be 
  too 
  far 
  

   from 
  coincident 
  in 
  time, 
  directly 
  to 
  my 
  temporary 
  bases. 
  

  

  Barometric 
  observations 
  on 
  the 
  Sierra 
  la 
  Sal 
  were 
  connected 
  by 
  a 
  

   system 
  of 
  vertical 
  angles 
  and 
  reduced 
  to 
  a 
  common 
  point, 
  for 
  the 
  attain- 
  

   ment 
  of 
  greater 
  accuracy. 
  

  

  In 
  1876, 
  my 
  observations 
  at 
  camps 
  were 
  referred 
  directly 
  to 
  White 
  

   Eiver 
  agency. 
  My 
  stations 
  and 
  other 
  points 
  were 
  referred 
  either 
  to 
  

   camps 
  or 
  directly 
  to 
  White 
  River 
  agency. 
  

  

  The 
  Uncompahgre 
  River, 
  after 
  leaving 
  the 
  San 
  Juan 
  Mountains, 
  in 
  

   which 
  it 
  heads, 
  flows 
  northward 
  through 
  Uncompahgre 
  Park. 
  This 
  is 
  

   a 
  small 
  but 
  fine 
  valley, 
  about 
  ten 
  miles 
  long 
  by" 
  two 
  wide. 
  It 
  is 
  the 
  

   favorite 
  summer 
  camping-place 
  of 
  the 
  Ute 
  Indians, 
  but 
  owing 
  to 
  the 
  

   elevation, 
  7,000 
  to 
  7,500 
  feet, 
  it 
  is 
  not 
  a 
  desirable 
  winter 
  resort. 
  

  

  At 
  the 
  foot 
  of 
  the 
  park, 
  a 
  large 
  branch, 
  known 
  as 
  Dallas 
  Fork, 
  enters 
  

   the 
  Uncompahgre 
  from 
  the 
  west. 
  Fine 
  meadows 
  extend 
  up 
  this 
  lork 
  

   for 
  four 
  or 
  five 
  miles. 
  Below 
  the 
  junction, 
  the 
  river 
  enters 
  a 
  caiion 
  in 
  a 
  

   plateau, 
  where 
  the 
  walls 
  are 
  about 
  500 
  feet 
  in 
  height. 
  This 
  caiion 
  ex- 
  

   tends 
  down 
  the 
  river 
  about 
  seven 
  miles. 
  Just 
  below 
  its 
  base, 
  on 
  the 
  

   west 
  side 
  of 
  the 
  river, 
  is 
  the 
  Uncompahgre 
  agency, 
  at 
  an 
  elevation 
  of 
  

   6,400 
  feet. 
  From 
  this 
  point 
  to 
  its 
  moiith, 
  the 
  river 
  flows 
  in 
  a 
  broad 
  valley, 
  

   of 
  an 
  average 
  width 
  of 
  15 
  miles 
  and 
  a 
  length 
  of 
  35, 
  containing 
  about 
  

   500 
  square 
  miles. 
  This 
  area 
  is 
  nearly 
  all 
  bench 
  land, 
  elevated 
  50 
  to 
  200 
  

   feet 
  above 
  the 
  river. 
  The 
  river 
  bottom-lands 
  have 
  a 
  width 
  of 
  one- 
  

   fourth 
  of 
  a 
  mile 
  to 
  a 
  mile. 
  The 
  soil 
  of 
  the 
  latter 
  is 
  good, 
  and 
  can 
  easily 
  

   be 
  made 
  productive 
  by 
  irrigation. 
  The 
  soil 
  of 
  the 
  bench 
  is 
  adobe 
  clay, 
  

   varied 
  by 
  occasional 
  patches 
  of 
  gravel. 
  Alkali, 
  everywhere 
  present, 
  

   becomes 
  moi^e 
  abundant 
  farther 
  down 
  the 
  valley. 
  Its 
  present 
  vegetable 
  

   product 
  is 
  in 
  the 
  main 
  part 
  sage. 
  White 
  sage 
  is 
  abundant 
  in 
  the 
  upper 
  

   part 
  of 
  the 
  valley, 
  with 
  a 
  little 
  bunch 
  and 
  grama 
  grass. 
  In 
  the 
  low^er 
  

   end, 
  even 
  sage 
  does 
  not 
  grow 
  with 
  much 
  animation, 
  and 
  the 
  field 
  is 
  

   almost 
  abandoned 
  to 
  cacti 
  and 
  sterility. 
  

  

  With 
  exception 
  of 
  the 
  Uncompahgre 
  and 
  three 
  small 
  branches 
  near 
  

   the 
  head 
  of 
  the 
  valley, 
  no 
  water 
  is 
  brought 
  in. 
  During 
  early 
  spring 
  

   most 
  of 
  the 
  water-courses 
  are 
  full, 
  but 
  this 
  lasts 
  a 
  few 
  days 
  only. 
  Two 
  

   small 
  branches 
  carry 
  water 
  all 
  the 
  year, 
  but 
  these 
  are 
  unimportant 
  for 
  

   irrigating 
  purposes. 
  About 
  eight 
  miles 
  below 
  the 
  agency, 
  a 
  small 
  

   stream 
  enters 
  the 
  valley 
  and 
  immediately 
  spreads 
  over 
  the 
  surface, 
  nat- 
  

   urally 
  irrigating 
  an 
  area 
  of 
  about 
  a 
  square 
  mile. 
  Here 
  a 
  family 
  of 
  Utes 
  

   are 
  engaged 
  in 
  cultivating 
  corn, 
  potatoes, 
  and 
  other 
  common 
  garden- 
  

   vegetables, 
  in 
  which 
  they 
  have 
  good 
  success, 
  although 
  occasionally 
  in- 
  

   terfered 
  with 
  by 
  early 
  frosts. 
  

  

  