fisher.]  COAL    IN    NORTHWESTERN    WYOMING.  355 
of  variation  in  thickness.  In  an  area  underlain  by  30  feet  of  coal, 
1  square  mile  would  contain  15,000,000  tons,  or,  supposing  that  on 
an  average  only  one-half  that  thickness  were  found,  there  would  be 
7,500,000  tons  of  coal.  A  determination  of  the  productive  capacity 
of  the  entire  Thermopolis  district  was  not  undertaken  in  the  present 
reconnaissance.  The  total  coal  acreage  of  this  region  can  be  only 
rudely  estimated,  for  no  systematic  prospecting  has  ever  been  con- 
ducted, but  coal  outcrops  may  be  seen  along  the  strike  of  the  beds  for 
several  miles,  and,  as  the  dip  is  uniform  and  moderately  low,  the  field 
is  undoubtedly  large. 
Coal  is  reported  to  occur  in  beds  of  a  thickness  sufficient  for  eco- 
nomic working  6  miles  southwest  of  Tensleep  post-office,  near  the  head 
of  some  small  tributaries  of  No  Wood  Creek.  Here  a  few  prospects 
have  been  made  from  which  a  small  amount  of  coal  is  taken.  The  coal 
is  said  to  be  of  good  quality  and  in  a  favorable  condition  for  mining 
on  a  more  extended  scale.  Reports  are  also  current  of  good  outcrops 
on  No  Wood  Creek,  about  12  miles  above  its  mouth,  and  at  the  head  of 
other  streams  near  by  that  rise  within  the  confines  of  the  Laramie  for- 
mation. This  part  of  the  Bighorn  Basin  is  thinly  populated  and  the 
demand  for  coal  is  slight,  therefore  little  prospecting  has  been  done. 
An  examination  of  this  district  was  not  undertaken,  but  as  it  is  situ- 
ated in  a  region  of  such  general  distribution  of  coal  deposits  it  is 
probable  that  this  area  will  be  found  to  be  productive. 
On  No  Wood  Creek,  about  25  miles  above  its  mouth,  there  is  a  small 
coal  district.  The  principal  interest  attached  to  this  locality  is  the 
fact  that  the  deposits  are  contained  in  the  basal  sandstones  of  the  so- 
called  Dakota  series,  less  than  50  feet  above  the  Morrison  formation. 
The  coal  has  been  prospected  at  frequent  intervals  for  2  or  3  miles 
along  the  strike,  which  here  trends  east- southeast,  but  at  present  opera- 
tions are  confined  to  one  opening  known  as  the  Diehl  &  Bell  mine. 
The  deposit  consists  of  two  benches  each  of  1  feet,  separated  by  a 
2-inch  la}<er  of  dark-colored  shale.  In  appearance  the  coal  is  dark, 
with  dull,  earth}^  luster,  conchoidal  fracture,  and  resembles  closety  a 
carbonaceous  shale.  The  analysis  shows  a  moderately  high  percentage 
of  fixed  carbon  and  volatile  matter,  a  low  per  cent  of  moisture,  but  an 
unusually  high  amount  of  ash.  It  weathers  slowly,  but  as  a  domestic 
fuel  it  does  not  give  general  satisfaction.  The  bed  thins  rapidly  to 
either  side  of  the  opening,  strongly  suggesting  the  lenticular  character 
of  the  deposit.  The  product  will  not  coke,  but  it  is  said  to  be  suitable 
for  welding  purposes.  The  accompanying  section  will  show  the  char- 
acter of  this  deposit. 
Section  at  Diehl  &  Bell  mine,  near  Tensleep,  Wyo. 
Ft.    In. 
Coal 4     0 
Dark-gray  slate 0    2 
Coal 4    0 
