COAL  ON   SOUTHWEST   SIDE   OF  BIGHORN   BASIN,   WYO.  201 
Cody  branch  of  the  Chicago,  Burlington  and  Quincy  Railroad;  Mee- 
teetse,  an  inland  town  on  Grey  Bull  River;  and  Kirby,  a  railroad 
station  near  the  Gebo  mines,  at  present  the  terminus  of  the  Worland- 
Kirby  extension  of  the  Burlington  Railroad.  Coal  beds  which  have 
sufficient  thickness  and  extent  to  be  of  local  interest  are  distributed 
throughout  the  fields,  but  deposits  of  commercial  importance  lie 
mainly  in  the  southern  part  of  the  basin. 
SURFACE  FEATURES. 
The  area  is  characterized  mostly  by  hilly  topography.  It  lies  on 
the  edge  of  a  broad  structural  basin,  in  a  zone  between  mountain  and 
plains,  where  the  strata  which  are  upturned  along  the  mountains  are 
being  rapidly  eroded.  These  conditions  have  produced  sharp  strike 
ridges  which  in  general  parallel  the  main  uplift  or  encircle  small  out- 
lying anticlines  or  domes.  The  field  is  crossed  at  short  intervals  by 
narrow  valleys  cut  by  rivers  or  creeks  which  rise  in  the  mountains  and 
flow  eastward  into  the  basin.  The  general  topographic  features  are 
modified  by  many  badland  areas,  plateau  remnants,  and  small  ero- 
sional  basins.  In  the  northern  part  of  the  area  Heart  Peak  rises  as 
an  isolated  mountain,  3,000  feet  above  the  general  level.  The  altitude 
of  the  field  averages  about  5,000  feet,  but  ranges  from  4,000  feet  on 
Clark  Fork  to  8,000  feet  on  Heart  Peak,  and  8,200  feet  in  the  south- 
western portion  of  the  area.  Variations  in  altitude  of  200  to  500  feet 
in  a  horizontal  distance  of  one-fourth  mile  are  not  uncommon,  and  at 
many  places  cliffs  rise  almost  perpendicularly  100  to  400  feet. 
The  fields  are  drained  by  three  rivers  and  many  smaller  streams 
which  rise  in  the  mountains  and  flow  eastward,  crossing  the  fields  in 
their  passage  to  Bighorn  River,  which  is  the  trunk  stream  of  the  basin. 
Clark  Fork,  the  northernmost  of  these  rivers,  flows  eastward,  then 
northeastward  beyond  the  boundaries  of  the  area  mapped ;  Shoshone 
River  crosses  the  area  near  Cody  in  a  gorge  100  to  150  feet  deep;  and 
Grey  Bull  River,  south  of  the  center,  is  a  swiftly  flowing  stream  with 
narrow  flood  plains  bordered  by  rugged  areas.  Bighorn  River  forms 
the  southeastern  limit  of  the  territory  examined  in  1007.  Between 
the  rivers  are  minor  streams,  notably  Pat  O'Hara,  Sage,  Meeteetse, 
Gooseberry,  Grass,  and  Cottonwood  creeks.  All  the  streams  arc  in  a 
youthful  stage  of  erosion,  generally  with  entrenched  valleys  and  basins 
having  moderately  steep  slopes  from  the  stream  courses  to  the  inter- 
stream  divides. 
