﻿BREEDING-GROUNDS 
  OF 
  C. 
  SPRETUS. 
  71 
  

  

  directly 
  northward 
  to 
  the 
  43d 
  parallel 
  of 
  latitude; 
  here 
  it 
  bends 
  north- 
  

   west, 
  reaching 
  about 
  the 
  113th 
  meridian, 
  where 
  it 
  crosses 
  the 
  northern 
  

   boundary 
  of 
  the 
  United 
  States, 
  varying 
  in 
  height 
  from 
  8,000 
  to 
  12,000 
  feet 
  

   above 
  sea 
  level, 
  with 
  peaks 
  here 
  and 
  there 
  shooting 
  up 
  to 
  14,000 
  feet. 
  

   The 
  heaviest 
  mountain 
  masses 
  are 
  found 
  in 
  Colorado 
  and 
  Northwestern 
  

   Wyoming, 
  the 
  former 
  being 
  interrupted 
  by 
  elevated 
  basins 
  or 
  parks 
  

   eight 
  to 
  ten 
  thousaud 
  feet 
  above 
  sea 
  level 
  ; 
  the 
  latter 
  by 
  valleys 
  extend- 
  

   ing 
  north 
  and 
  south. 
  Passing 
  westward 
  from 
  this 
  eastern 
  mountain 
  wall 
  

   (for 
  such 
  it 
  really 
  is), 
  in 
  Colorado 
  and 
  Wyoming, 
  we 
  traverse 
  a 
  broad, 
  

   barren 
  plain, 
  with 
  Artemisia 
  as 
  its 
  characteristic 
  plant, 
  until 
  we 
  reach 
  

   the 
  Wasatch 
  range 
  or 
  western 
  wall, 
  in 
  Utah. 
  This 
  broad 
  area, 
  which 
  

   averages 
  in 
  elevation 
  about 
  6,000 
  feet, 
  is 
  here 
  and 
  there 
  broken 
  into 
  

   rolling 
  hills 
  with 
  occasional 
  ridges, 
  and 
  is 
  almost 
  entirely 
  free 
  from 
  

   forests. 
  Passing 
  to 
  the 
  west 
  side 
  of 
  the 
  Wasatch, 
  in 
  Utah, 
  we 
  enter 
  

   the 
  great 
  Salt 
  Lake 
  basin, 
  which 
  is 
  also 
  mostly 
  barren, 
  with 
  scanty 
  

   vegetation, 
  and 
  is 
  interrupted 
  by 
  numerous 
  narrow 
  ridges 
  running 
  north 
  

   and 
  south. 
  It 
  has 
  an 
  average 
  elevation 
  of 
  about 
  4,000 
  feet. 
  Passing 
  

   west 
  of 
  the 
  Teton 
  range, 
  from 
  Wyoming 
  into 
  Idaho, 
  we 
  enter 
  upon 
  the 
  

   broad, 
  level, 
  and 
  comparatively 
  barren 
  valley 
  of 
  Snake 
  Eiver,, 
  which 
  is 
  

   also 
  without 
  forests. 
  The 
  portion 
  of 
  Montana 
  west 
  of 
  the 
  first 
  range 
  is 
  

   rugged, 
  being 
  broken 
  into 
  a 
  series 
  of 
  ridges 
  and 
  valleys 
  running 
  north 
  

   and 
  south, 
  more 
  or 
  less 
  clothed 
  with 
  coniferous 
  forests. 
  The 
  chief 
  tim- 
  

   ber 
  areas 
  in 
  this 
  extensive 
  region 
  are 
  found 
  upon 
  the 
  mountain 
  masses 
  

   in 
  Colorado 
  and 
  Northwestern 
  Wyoming 
  and 
  in 
  the 
  western 
  part 
  of 
  

   Montana. 
  

  

  The 
  main 
  or 
  eastern 
  range, 
  as 
  heretore 
  stated, 
  is 
  flanked 
  on 
  the 
  east 
  

   by 
  a 
  broad 
  and 
  treeless 
  plain 
  extending 
  from 
  its 
  base 
  eastward 
  to 
  the 
  

   Missouri 
  Eiver. 
  That 
  portion 
  of 
  this 
  plain 
  where 
  it 
  leaves 
  the 
  mountains 
  

   in 
  Colorado 
  and 
  Wyoming 
  has 
  generally 
  an 
  elevation 
  of 
  from 
  5,000 
  to 
  

   6,000 
  feet 
  and 
  slopes 
  eastward 
  at 
  a 
  rate 
  varying 
  from 
  6 
  to 
  15 
  feet 
  per 
  

   mile. 
  As 
  we 
  proceed 
  northward 
  along 
  the 
  mountain 
  flank 
  from 
  the 
  

   Black 
  Hills, 
  the 
  elevation 
  grows 
  less 
  and 
  less, 
  so 
  that 
  the 
  great 
  barren 
  

   plateau 
  of 
  Central 
  Montana 
  ranges 
  from 
  2,000 
  to 
  3,000 
  feet 
  above 
  sea 
  

   level. 
  

  

  The 
  term 
  u 
  barren" 
  as 
  here 
  used 
  is 
  not 
  to 
  be 
  taken 
  in 
  the 
  sense 
  of 
  

   desert, 
  but 
  as 
  implying 
  without 
  arboreal 
  vegetation, 
  and 
  as 
  usually 
  

   clothed 
  with 
  a 
  moderate 
  growth 
  of 
  grass, 
  sage, 
  and 
  other 
  plants 
  of 
  a 
  

   similar 
  nature 
  adapted 
  to 
  a 
  dry 
  climate, 
  and 
  generally 
  suited 
  for 
  pas- 
  

   turage. 
  The 
  forests, 
  wherever 
  found, 
  consist 
  almost 
  entirely 
  of 
  pine 
  

   and 
  fir, 
  and 
  are 
  confined 
  almost 
  entirely 
  to 
  the 
  mountain 
  ranges 
  where 
  

   the 
  snow 
  is 
  most 
  abundant. 
  

  

  There 
  is 
  no 
  part 
  of 
  this 
  district 
  where 
  agricultural 
  operations 
  can 
  be 
  

   carried 
  on 
  without 
  irrigation, 
  as 
  the 
  rainfall 
  seldom 
  exceeds, 
  in 
  any 
  

   portion, 
  20 
  inches 
  in 
  a 
  year, 
  and 
  in 
  many 
  parts 
  does 
  not 
  average 
  more 
  

   than 
  6 
  or 
  7. 
  The 
  air 
  is 
  very 
  dry, 
  the 
  relative 
  humidity 
  sometimes 
  fall- 
  

  

  