86  CONTRIBUTIONS  TO   ECONOMIC   GEOLOGY,  1907,  PART  II. 
NE.  i  sec.  35,  T.  8  N.,  R.  10  E.,  a  few  feet  south  of  the  highway,  on 
the  bank  of  a  small  creek.  It  lies  above  a  gray  sandstone  having 
Eagle  characteristics,  but  is  only  3  inches  thick.  In  a  small  canyon 
in  sec.  23  of  the  same  township,  where  coal  is  reported,  a  foot  of 
black  shale  was  found  in  the  trail  on  the  west  bank  of  the  stream. 
This  carbonaceous  shale  is  in  the  Kootenai  formation,  and  probably 
represents  the  horizon  of  the  coal  which  is  mined  in  the  vicinity  of 
Lewistown,  Fergus  County,  and  Great  Falls,  Cascade  County. 
Prospects  at  the  mouth  of  Warm  Spring  Creek,  on  the  south  fork 
of  Musselshell  River,  attract  attention  because  they  are  close  to  the 
road  and  show  black  dumps,  but  on  examination  it  was  found  that 
the  bed  consists  of  3  or  4  feet  of  black  shale  containing  about  1  foot 
of  coal  which  appears  to  be  of  low  grade.  The  rocks  at  this  point 
stand  at  an  angle  of  69°  and  thus  add  to  the  difficulty  of  obtaining 
fuel.  The  coal  is  believed  to  be  in  the  Eagle  sandstone.  Weed 
says  of  this  locality :  a 
At  the  mouth  of  Warm  Spring  Creek  a  coal  seam  has  been  exposed.  The  seam  is 
of  sufficient  thickness  and  purity  to  be  workable,  but  the  attitude  is  not  favorable, 
the  beds  being  vertical  and  the  exposure  but  a  few  feet  above  probable  water  level. 
The  outcropping  sandstones  can,  however,  be  traced  up  the  slopes  southward,  and 
the  area  will  furnish  an  abundance  of  fuel  when  the  demand  warrants  exploitation. 
In  another  place  b  Weed  says  of  the  coal  on  Warm  Spring  Creek: 
"A  coal  seam  exposed  on  the  bench  land  adjoining  Warm  Springs 
Creek  has  been  opened  at  several  places,  but  has  so  far  proved  too 
impure  to  encourage  development." 
Reports  of  the  occurrence  of  coal  on  Checkerboard  Creek,  on  the 
north  flank  of  Castle  Mountain,  12  miles  northwest  of  Lennep,  led 
to  inquiries  which  resulted  in  the  following  information  from  Post- 
master Hull,  of  Delpine,  on  the  north  fork  of  Musselshell  River.  Twelve 
or  fifteen  years  ago  a  coal  bed  about  18  (?)  inches  thick  was  opened 
and  operated  on  the  head  of  Checkerboard  Creek.  The  locality  is 
about  4  miles  up  the  creek,  three-fourths  of  a  mile  above  a  limestone 
canyon,  300  yards  up  a  steep  drain  on  the  left  near  the  old  Castle 
road.  Several  hundred  tons  of  coal  were  taken  to  White  Sulphur 
Springs  for  domestic  use  and  proved  fairly  satisfactory  except  that 
the  quantity  of  sulphur  contained  in  the  coal  gave  off  fumes  that  per- 
vaded the  town.  On  account  of  the  high  percentage  of  sulphur,  the 
coal  is  not  good  for  blacksmithing.  Mining  was  abandoned  because 
of  the  thinness  and  poor  quality  of  the  coal. 
Weed  says  of  this  locality : c 
A  thin  seam  of  coal  occurring  beneath  the  Dakota  quartzite  near  the  forks  of  Checker- 
board Creek  has  been  mined  in  a  small  way  for  Messrs.  Spencer,  Main  &  Heitmann,  of 
White  Sulphur  Springs.     The  seam  is  hardly  thick  enough  or  the  product  of  sufficiently 
a  Weed,  W.  H.,  and  Pirsson,  L.  V.,  Geology  of  the  Castle  Mountain  mining  district,  Montana:  Bull. 
U.  S.  Geol.  Survey  No.  139,  1896,  p.  148. 
b  Little  Belt  Mountains  folio  (No.  56),  Geologic  Atlas  U.  S.,  U.  S.  Geol.  Survey,  1899. 
c  Bull.  U.  S.  Geol.  Survey  No.  139,  1896,  p.  148. 
