84  CONTRIBUTIONS   TO    ECONOMIC    OEOLOGY,   1907,   PART   II. 
several  points,  but  nowhere  has  it  proved  of  sufficient  value  to  develop 
except  in  a  small  area  west  of  the  Crazy  Mountains,  on  the  head  of 
Sixteenmile  Creek,  where  a  bank  has  been  operated  for  a  number  of 
winters  but  is  now  idle. 
Coal  or  coaly  shale  was  discovered  in  the  Eagle  sandstone  at  short 
distances  throughout  the  area  examined,  but  at  too  few  places  to 
determine  if  it  occurs  in  more  than  one  part  of  the  formation  or  if  it 
is  a  continuous  bed.  The  writer  believes  that  the  Eagle  coal  may  be 
absent  in  many  places.  In  the  Judith  River  formation  lenses  of  coal 
of  short  lateral  extent  and  a  few  inches  thick  are  not  uncommon. 
Beds  of  similar  character  are  also  found  in  the  Laramie  and  Fort 
Union  formations. 
The  localities  where  coal  is  found  in  the  area  here  discussed  are  so 
few  that  they  can  be  enumerated  and  described  in  detail.  Beginning 
at  the  east,  the  first  known  occurrence  is  a  prospect  south  of  Shaw- 
mut,  from  which  Mr.  Crawford a  has  taken  a  few  loads  of  coal.  It  is 
situated  on  a  small  branch  of  Mud  Creek  which  cuts  through  ridges 
of  upturned  rocks  in  sec.  13,  T.  6  N.,  R.  17  E.  The  coal  is  exposed 
on  the  south  flank  of  the  northernmost  ridge  close  to  the  stream  and 
is  inclined  at  an  angle  of  30°.  There  are  two  beds  of  coal,  each  less 
than  1  foot  thick  and  separated  by  several  feet  of  shale.  As  the  coal 
makes  the  flank  of  the  ridge,  it  can  be  obtained  by  stripping  a  small 
amount  of  soil.  There  is  not  enough  within  easy  reach,  however,  to 
induce  near-by  ranchers  to  mine  it  for  regular  use.  It  is  subbitu- 
minous  in  character  and  would  be  of  some  value  if  it  had  a  greater 
thickness. 
Two  miles  northwest  of  this  locality,  in  sec.  10,  where  Mud  Creek 
cuts  through  the  ridges  formed  by  the  upturned  Eagle  and  Claggett 
formations,  this  same  coal  bed,  or  one  in  relatively  the  same  position, 
has  been  exposed  on  the  east  side  of  the  creek  south  of  the  first  ridge. 
The  outcrop  of  the  coal  was  hidden  when  the  locality  was  visited, 
but  it  is  believed  to  be  not  over  a  few  inches  thick. 
On  Joe  Creek,  a  branch  of  Mud  Creek,  in  sec.  1,  T.  6  N.,  R.  16  E., 
there  is  a  prospect  drift  in  the  bluff  below  a  sheep  shed  which  shows  a 
coal  bed  28  inches  thick.  As  the  bed  includes  an  18-inch  band  of 
bone  and  very  dirty  coal,  the  amount  of  fuel  is  not  over  10  inches, 
and  therefore  it  has  no  value.  It  lies  under  a  massive  sandstone  in 
the  lower  part  of  the  Judith  River  formation.  On  Holcomb  Creek, 
1  mile  south  of  this  locality,  the  same  bed  is  exposed  in  the  south 
bank  of  the  stream  for  a  few  rods  and  has  a  thickness  of  about  30 
inches.  It  appears  to  be  subbituminous  in  quality  and  is  variable 
in  thickness,  decreasing  within  a  few  rods  to  less  than  2  feet. 
Where  the  Eagle  sandstone  crosses  Joe  Creek,  in  sec.  2  of  the  same 
township,  the  presence  of  coal  or  coaly  shale  is  shown  by  fragments 
a  Stanton,  T.  W.,  and  Hatcher,  J.  B.,  The  geology  and  paleontology  of  the  Judith  River  beds:  Bull. 
U.  S.  Geol.  Survey  No.  257, 1905,  p.  60. 
