BENTONITE    OF    LARAMIE    BASIN,    WYOMING.  447 
thickness  of  4  to  5  feet,  and  dips  4°  or  5°  to  the  south  with  the  slope  of  the  hill,  the  bed 
being  thus  exposed  over  several  acres.  In  working  the  clay  pit  the  top,  consisting  of  a 
few  inches  of  weathered  debris,  is  stripped  off  and  the  clay  is  loaded  into  wagons  and 
hauled  6  miles  to  Wilcox,  the  nearest  railway  station.  The  elay  is  shipped  loose  in  box 
cars,  either  in  lumps,  as  it  naturally  comes  from  the  pit,  or  as  the  fine  loose  powder  which 
results  from  the  weathering  of  the  clay. 
LinscotVs. — About  3  miles  southeast  of  Taylor's  a  pit  was  opened  in  1897  in  NW.  \  see.  17, 
T.  21  N.,  R.  75  W.,  near  the  old  line  of  the  railroad.  About  20  carloads  W(  re  shipped 
before  the  readily  accessible  supply  was  exhausted.  Another  site  was  opened  up  in  the 
SE.  I  NE.  I  sec.  14,  T.  22  N.,  R.  76  W.,  on  the  north  side  of  Rock  Creek,  from  which  about 
100  carloads  have  been  shipped.  The  thickness  and  relations  are  analogous  to  I  hose  of 
Taylor's  bank. 
Cassa  Mining  Company. — This  claim  is  located  in  the  N.  §  sec.  10,  T.  22  N.,  R.  76  W. 
Nothing  but  development  work  has  been  done  up  to  the  present  time,  and  only  sample 
consignments  have  been  shipped.  The  claim  takes  in  a  strip  a  mile  in  length,  the  occur- 
rence of  the  clay  being  similar  to  those  previously  described. 
Sam  White's.— This  property  lies  in  the  NW.  |  sec.  20,  T.  22  N.,  R.  77  W.,  on  the  south 
slope  of  Como  Ridge.  Th's  occurrence  of  the  clay  is  similar  to  the  others  except  that 
the  dip  of  the  rocks  is  steeper  and  a  smaller  area  is  uncovered.  Only  development  work 
has  been  done. 
Cosgriff's.—This  claim  is  located  in  the  NW.  \  sec,  12,  T.  21  N.,  R.  75  W.,  near  the 
prominent  point  locally  known  as  Chalk  Bluff.  The  thickness,  geologic  relations,  and 
quality  of  the  outcrop  are  the  same  as  in  the  occurrences  already  described.  No  clay 
has  been  shipped. 
The  foregoing  comprise  all  the  occurrences  of  this  clay  which  have  assumed  commercial 
importance  in  the  Rock  River  region,  the  type  locality.  They  are  strung  along  the  outcrop 
of  the  Benton  formation  for  a  distance  of  20  miles.  The  bed  of  clay  is  probably  persistent 
throughout  that  distance,  though  its  outcrop  is  not  always  apparent.  Bentonite  has 
been  noted  in  a  few  localities  elsewhere  in  the  Laramie  basin. 
Hutton  Lakes. — Along  the  bluff  on  the  northwest  shore  of  the  northern  of  the  Ilutton 
Lakes  for  a  distance  of  200  yards  a  bed  of  bentonite  makes  a  white  band  in  the  black 
shale  of  the  Benton  formation.  This  bed  is  from  3  to  4  feet  thick  and  dips  about  S.  85°  W. 
The  Mowry  beds  outcrop  to  the  east  and  evidently  dip  beneath  the  clay.  The  quality 
is  apparently  good. 
Sand  Creek.— Near  the  middle  of  the  north  side  of  sec.  2,  T.  13  N.,  R.  75  W.,  in  the 
east  bank  of  Sand  Creek,  a  4-foot  bed  of  characteristic  bentonite  is  underlain  by  20  feet 
of  soft  black  shale  and  overlain  by  fossiliferous  sandstone  and  light  and  dark  shales.  The 
relation  of  the  bentonite  to  the  Mowry  beds  is  not  clear,  but  the  probabilities  are  that  this 
clay  is  beneath  the  Mowry. 
Riverside.— On  the  Riverside  ranch,  in  the  NE.  £  sec,  14,  T.  13  N.,  R.  76  W.,  a  bed 
of  much-weathered  bentonite  less  than  2  feet  in  thickness  lies  a  few  feet  above  the  Mowry 
beds.     In  the  SE.  \  sec.  6,  T.  14  N.,  R.  75  W.,  the  bed  is  reported  to  thicken  to  4  feet. 
PRODUCTION   AND   PRICES. 
From  1888  to  1895,  inclusive,  the  output  of  bentonite  averaged  about  60  tons  annually. 
From  that  time  it  gradually  increased  until  in  1902  it  is  reported  to  have  been  1,200  tons. 
With  the  closing  down  of  the  western  paper  mills  the  output  almost  stopped,  and  in  1905 
only  a  very  small  amount  was  shipped. 
In  the  early  period  from  1888  to  1895  the  price  averaged  $25  per  ton,  f.  o.  b.  cars.  The 
price  then  dropped  to  $5,  but  later  rose  to  $6  and  $7  per  ton.  The  total  production  to 
date  is  approximately  6,000  tons,  with  a  value  of  $45,000. 
