358  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull. 225. 
Section  of  trial  pit  at  Wyoming  Coal  and  Fuel  Company,  Garland,  Wyo. 
Ft.    In. 
I  >ark-gray,  compact  clay 4    0 
Coal 4    3 
Section  at  Garland  Coal  Company's  mine,  Garland,  Wyo. 
Ft.    In. 
Dark-gray  clay 2    0 
Coal....' 3     6 
Coal  with  streaks  of  carbonaceous  shale 2    6 
Silver  Tip  district. — This  district  is  located  on  the  divide  between 
Clark  Fork  and  Gray  Bull  River,  near  the  head  of  Cottonwood  Creek. 
In  the  vicinity  there  are  several  small  openings,  of  which  the  Silver 
Tip  mine  is  the  most  important.  The  work  at  this  place  so  far  can 
be  regarded  only  as  development,  although  about  500  tons  of  coal  of  a 
good  quality  have  been  taken  out.  The  total  thickness  of  the  deposit 
is  5  feet,  with  two  partings  of  impure  coal  and  a  thin  layer  of  soft, 
light-colored  clay.  The  tunnel  extends  60  feet  from  the  outcrop  at 
present,  but  plans  for  more  extensive  development  have  been  consum- 
mated. The  analysis  of  this  coal  shows  a  rather  high  percentage  of 
fixed  carbon  and  volatile,  combustible  matter,  with  a  low  per  cent  of 
water  and  ash.  Of  principal  interest  is  the  fact  that  the  coal  occurs 
in  the  upper  sandy  division,  which  is  the  highest  member  of  the  Lar- 
amie in  the  Bighorn  Basin.  It  is  in  the  same  formation  as  the  Red 
Lodge  coal  measures,  and  as  these  deposits  have  been  traced  more 
than  150  miles  to  the  northwest,  showing  marked  continuity,  it  seems 
reasonable  to  expect  their  southeastern  extension  to  be  found  in  the 
high  divide  south  of  Clark  Fork,  the  vicinity  of  the  Silver  Tip  mine. 
Some  prospecting  has  been  done  in  this  region,  but,  judging  from  the 
productivity  of  these  measures  elsewhere,  it  is  believed  that  a  careful, 
systematic  investigation  would  probably  result  in  the  location  of  other 
valuable  coal  beds.  A  section  of  the  deposits  at  the  Silver  Tip  mine 
is  here  given: 
Section  at  Silver  Tip  mine,  Wyoming. 
Ft.    In. 
Coal 1     10 
Bony  coal 0      2 
Coal 0      6 
Light-gray  clay 0       1 
Coal 0      5 
Impure  coal 0      2 
Coal 3      3 
The  data  obtained  in  the  present  reconnaissance,  concerning  the 
occurrence  of  coal  in  the  Bighorn  Basin,  is  on  the  whole  encouraging. 
While  the  region  can  probably  not  be  regarded  as  one  of  general 
promise  for  large  production  or  shipment,  yet  there  are  two  or  more 
localities  within  the  basin  where  the  quality  of   the  coal,  combined 
