ST.    JOE    RIVER    BASIN,   IDAHO.  133 
way,  near  the  few  trails  which  cross  the  district  from  north  to  south,  or  adjacent  to  canoe 
navigation  on  St.  Joe  River.  From  the  evidence  adduced  it  appears  that  placer  gold  was 
discovered  on  the  headwaters  of  St.  Joe  River  at  what  is,  called  the  St.  Joe  Basin  as  early 
as  1870  by  prospectors  crossing  the  divide  from  Iron  Mountain.  Montana.  This  district, 
however,  is  so  remote  from  transportation  and  the  placers  are  of  such  low  grade  that  the 
ground  has  not  yet  been  systematically  worked,  though  small  amounts  of  gold  have  been 
obtained.  The  search  for  lead-silver  and  copper  ores  was  inaugurated  in  L884  or  L885, 
after  the  discovery  of  the  valuable  lead-silver  deposits  of  the  Coeur  d'Alenes. 
LEAD-SILVER    DEPOSITS. 
Croppings  of  rock  containing  galena  were  examined  in  prospect  holes  at  several  points 
along  Slate  Creek,  near  the  trail  from  Wallace  to  St.  Joe  River,  in  T.  46  N.,  Rs.  4  and  5  E.  ■ 
also  east  of  North  Fork  of  St.  Joe  River  in  T.  45  N.,  R.  6  E.  Similar  mineral  indications 
on  which  considerable  time  and  money  have  been  spent  occur  in  the  northern  part  of 
T.  46  N.,  Rs.  1  and  2  E.,  just  outside  the  area  under  investigation.  The  occurrence  of 
galena-bearing  rock  at  a  number  of  other  localities  not  personally  examined  was  indi- 
cated by  the  testimony  of  various  witnesses  adduced  at  the  hearing.  Most  of  the  pros- 
pects examined  lie  within  a  belt  a  few  miles  wide  extending  from  T.  45  N.,  R.  6  E.,  in  a 
west-northwest  direction  to  and  beyond  the  limits  of  the  district  under  investigation.  In 
some  instances  the  galena-bearing  rock  consists  of  so-called  "iron  cap"  or  gossarn,  a  mix- 
ture of  hematite,  limonite,  and  quartz  containing  some  unaltered  galena  which  can  easily 
be  recognized  when  the  specimens  are  newly  broken.  In  many  of  the  prospect  holes, 
however,  the  galena  is  found  to  be  disseminated  in  small  grains  and  veinlets  through  the 
country  rock,  which  on  the  surface  is  yellowish  brown  from  iron  stains.  In  such  cases 
the  galena  is  associated  with  more  or  less  siderite  and  sphalerite,  together  with  some 
pyrite  and  chalcopyiite.  This  association  of  minerals  resembles  that  in  the  ores  from 
some  of  the  mines  of  the  Coeur  d'Alene  district/'  which  have  replaced  the  country  rock 
in  proximity  to  mineralized  fissures  or  fractures. 
In  sec.  14,  T.  46  N.,  R.  5  E.,  gossan,  consisting  largely  of  limonite,  in  which  there  is  some 
unaltered  galena,  is  exposed  in  several  prospect  holes  which  have  been  abandoned  and  are 
so  much  caved  in  that  the  nature  of  the  occurrence  can  not  be  determined.  In  sec.  13, 
one-fourth  mile  southeast  of  this  locality,  the  bed  rock  exposed  in  a  steep  hillside  shows 
considerable  disturbance  and  an  overturned  close  fold,  but  no  definite  fissures  or  fractures 
were  observed.  Nearly  all  the  rocks  here  are  iron  stained  and  in  some  places  contain 
galena  disseminated  in  small  masses.  A  tunnel  about  40  feet  long  was  driven  several 
years  ago,  when,  it  is  reported,  considerable  galena  ore  could  have  been  obtained,  some 
of  which  was  rich  enough  for  shipping.  No  definite  vein  or  ledge,  however,  was  found. 
In  the  NW.  \  sec.  11,  about  three-fourths  of  a  mile  northwest  of  the  prospects  described, 
a  3  or  4  foot  bed  of  quartzite  containing  disseminated  siderite,  together  with  galena;, 
sphalerite,  pyrite,  and  chalcopyrite,  is  exposed  in  a  tunnel  30  feet  long.  This  mineral- 
ized bed  is  overlain  by  a  fissile  shaly  bed  which  is  not  mineralized.  It  lies  nearly  hori- 
zontal and  its  outcrop  can  be  traced  for  some  distance  along  the  hillside.  No  definite 
indication  of  a  mineralized  fracture  or  fissure  has  been  found  here,  though  near  the  end 
of  the  tunnel  there  is  a  aone  4  or  5  feet  wide  in  which  the  rock  is  broken  by  many  parallel 
joints  which  strike  N.  20°  W.  and  are  nearly  vertical. 
About  1J  miles  west  of  these  prospects  there  are  a  number  of  locations  on  the  head- 
waters of  the  West  Fork  of  Slate  Creek  and  near  the  southwest  corner  of  sec.  9.  In  one 
prospect  hole  examined  mineralized  quartzite  containing  galena  and  sphalerite  similar  to 
that  already  described  was  found.  No  definite  indications  of  any  mineralized  fracture  or 
fissure  were  seen  here  by  the  writer,  but  from  the  testimony  presented  ai  the  hearing  it 
is  evident  that  a  heavy  "iron  cap"  consisting  mainly  of  vein  quartz  and  botryoidal  hema- 
tite has  been  discovered  and  partially  developed.     This  material  when  assayed  showed 
aRansome,  F.  L.,  op.  cit.,  pp.  293-298. 
