SHERIDAN    COAL   FIELD,    WYOMING.  139 
A  shallow  prospect  in  the  E.  J  sec.  23  of  the  same  township  exposes 
5  feet  of  coal  in  the  upper  part  of  the  Monarch  bed.  The  mine  at 
Kooi,  near  the  center  of  the  same  section,  was  being  driven  on  the 
lower  7  feet  6  inches  of  the  same  bed  in  August,  1907,  and  the  operator 
reported  that  an  equal  thickness  of  coal  was  left  in  the  roof.  The 
main  entry  had  then  been  driven  but  a  few  hundred  feet  from  the 
mouth. 
Numerous  drill  holes  have  been  made  in  prospecting  for  the  Mon- 
arch coal  on  both  sides  of  the  Tongue  River  valle}r.  Some  of  the 
records  note  the  presence  of  this  bed  as  follows: 
Thickness  of  Monarch  coal  bed  in  Tongue  River  valley  as  shoivn  by  drill  holes. 
Ycet. 
T.  57  N.,  R.  85  W.:  SE.  i  sec.  23 18 
Near  center  sec.  25 29 
NE.  i  sec.  26 18 
T.  57  N.,  R.  84  W.:  SW.  \  sec.  19 29 
Near  SE.  cor.  sec.  19 34 
NE.  |  sec.  9 20 
NW.  i  sec.  10 20 
At  the  north  side  of  the  Big  Goose  Creek  valley,  near  the  east  side 
of  sec.  3,  T.  55  N.,  R.  85  W.,  a  mine  known  locally  as  the  Black  Dia- 
mond exposes  12  feet  of  clean  coal  underlain  by  3  feet  6  inches  of 
coal  and  shale  in  thin  layers.  The  same  bed  has  been  mined  for  local 
use  at  several  places  in  the  vicinity  of  the  Black  Diamond  mine. 
A  small  mine  has  been  developed  by  Mr.  Moore  in  the  S.  I  sec.  11, 
T.  55  N.,  R.  85  W.  It  is  presumed  that  this  is  the  same  bed  as  that 
of  the  Black  Diamond  mine.  The  bed  is  11  feet  thick,  but  only  the 
lower  9  feet  is  mined. 
In  the  Beaver  Creek  mine,  in  the  SE.  \  sec.  14,  T.  55  N.,  R.  85  W., 
the  coal  bed  has  the  following  section: 
Section  of  coal  bed  at  Beaver  Creek  mine,  in  sec.  14,  T.  ,5,r>  X.,  R.  85  II'. 
Shale.  Feet. 
Coal 6-  7 
Shale 1 
Coal 12 
Shale,  blue. 
Total  workable  coal 18-19 
The  upper  bench  at  this  mine  is  left  in  the  roof. 
The  Black  Diamond,  Moore,  and  Beaver  Creek  mines  are  operated 
chiefly  in  the  fall  to  supply  Sheridan  with  domestic  fuel. 
DIETZ    COAL    BEDS. 
Three  workable  coal  beds  have  been  located  on  fche  cast  side  of 
Goose  Creek  from  Tongue  River  southward  for  a  distance  of  aboul  3 
miles.     They  are  known  locally  as  the  Dietz  coals  because  of  their 
