INVESTIGATIONS    OF    METALLIFEROUS    ORES.  19 
WASHINGTON. 
During  the  last  season  A.  J.  Collier  has  been  occupied,  by  order  of 
the  Secretary  of  the  Interior  and  in  association  with  an  officer  of 
the  Land  Office,  in  examining  placer  lands  on  the  Colville  Reservation 
and  along  the  Columbia  and  Sanpoil  rivers,  for  the  purpose  of  deter- 
mining whether  certain  placer  locations  were  taken  up  in  good  faith. 
He  has  utilized  the  geological  information  obtained  during  this  work 
for  an  article  on  the  geological  relations  of  the  placer  mines  of  that 
region,  which  will  be  found  in  this  bulletin. 
WYOMING. 
During  an  examination  of  the  important  iron-ore  deposits  near 
Hartville,  in  Wyoming,  S.  H.  Ball  has  made  some  studies  of  the 
copper  deposits  that  were  worked  in  this  region  before  the  iron  ore 
became  valuable.  These  are  of  rather  unusual  form,  and  Mr.  Ball's 
description,  which  appears  in  this  bulletin,  will  be  interesting  to  stu- 
dents of  copper  deposits. 
In  connection  with  an  examination  of  the  coal  basins  in  the  western 
part  of  Wyoming,  A.  R.  Schultz  has  made  a  study  of  gold-placer 
deposits  along  upper  Snake  River  and  some  comparative  investiga- 
tions of  placers  on  the  same  river  in  the  western  part  of  Idaho.  These 
placers  are  highly  interesting  because  of  the  extremely  minute  parti- 
cles in  which  the  gold  is  found — so  minute  that  they  evidently  must 
have  suffered  an  immense  amount  of  trituration  during  the  very  long 
journey  from  their  original  source  in  the  rocks.  Mr.  Schultz's  article 
gives  an  account  of  the  various  attempts  to  work  these  placers  and 
the  results  of  tests  of  the  black  sands  collected  during  the  work,  which 
show  the  character  of  the  various  heavy  minerals  associated  with  the 
gold. 
