NORTHERN    IDAHO    AND    NORTHWESTERN    MONTANA.  51 
PROSPECT  CREEK. 
Location. — Prospect  Creek  heads  in  the  Coeur  d'Alene  Mountains  near  Thompson  Pass. 
It  flows  into  Clark  Fork  near  Thompson  Falls,  and  is  just  across  the  divide  to  the  noil heast 
of  the  Cceur  d'Alene  mining  district. 
Mines  and  properties. — The  Rosebud  Mining  Company  is  exploring  several  claims  near 
the  mouth  of  Rosebud  Creek,  a  small  tributary  which  enters  Prospect  Creek  about  9  miles 
above  its  mouth.  A  vein  of  white  quartz  has  been  found  by  this  company  in  the  upper  part 
of  the  Prichard  formation.  One  of  the  owners  reports  that  it  carries  some  silver  chloride 
and  over  $100  per  ton  in  gold  in  the  weathered  zone  at  the  surface. 
The  Montana  Standard  group  of  four  claims  is  on  Prospect  Creek  about  1 1  miles  above  its 
mouth.  The  vein  is  associated  with  a  massive  basic  dike  which  cuts  a  country  rock  of  the 
Burke  formation.  An  adit  driven  on  the  east  contact  of  this  dike  shows  irregular  masses 
of  white  quartz  carrying  galena.  About  400  feet  from  the  mouth  of  this  tunnel  a  fairly 
well-defined  cross  lead  runs  N.  20°  E.  and  dips  70°  E.  It  shows  some  evidence  of  shearing 
and  carries  galena  and  siderite.  On  the  west  side  of  the  dike  a  flat  vein  outcrops.  It  is  3 
to  4  feet  thick,  strikes  about  N.  15°  E.  and  dips  15°  W.  No  connection  between  this  vein 
and  the  ore  deposit  on  the  east  side  of  the  dike  was  apparent.  The  ore  seems  to  lie  in  irreg- 
ular bunches  and  cross  fissures  along  the  east  contact  of  the  dike.  The  examination  of  this 
property  was  very  hurried,  but  it  would  seem  advisable  in  the  course  of  the  present  active 
development  work  to  explore  the  east  contact  of  the  dike. 
A  few  miles  farther  up  Prospect  Creek  an  antimony  vein  occurs  from  which  a  considerable 
amount  of  ore  is  said  to  have  been  shipped  some  years  ago.  This  property  is  "now  idle. 
Other  claims  have  been  located  on  this  creek,  but  very  little  development  work  has  been  done 
on  them.  A  wagon  road  to  Thompson  Falls  and  Murray  furnishes  convenient  access  to  the 
region. 
MINING  PROPERTIES  NOT  VISITED. 
The  Buckhorn,  a  few  miles  east  of  Mooyie  River  and  about  10  miles  above  its  mouth,  is 
a  producer  of  gold  and  shows  some  lead.  So  far  as  present  development  has  gone  the  ore 
is  free  milling.  A  10-stamp  mill  has  recently  been  installed  and  shipments  were  expected 
to  begin  shortly.  Some  copper  properties  were  reported  to  have  been  prospected  at  the 
headwaters  of  Bull  River,  but  very  little  actual  development  work  has  been  done  on  them. 
3n  Rainy  Creek  north  of  Libby  is  a  prospect  in  a  contact  deposit  from  which  some  fair 
samples  of  galena  have  been  taken. 
MISSOULA  VALLEY,  a 
The  valley  of  Missoula  River  below  Missoula  has  been  and  is  still,  though  perhaps  to  a 
esser  extent  than  formerly,  the  scene  of  considerable  mining  activity.  Large  amounts  of 
*old  have  been  taken  from  placers  on  the  tributaries.  Copper  deposits  are  being  developed 
n  the  mountains  south  of  the  river,  but  their  future  value  can  not  as  yet  be  predicted  with 
onfidence.  North  of  the  river  the  veins  are  chiefly  of  galena,  but  few  of  these  have  been 
developed.  The  only  property  visited  was  the  Iron  Mountain  mine,  situated  about  5  miles 
lorth  of  Iron  Mountain  station  on  the  Northern  Pacific  Railway. 
IRON   MOUNTAIN   MINE. 
This  property,  once  the  most  important  in  the  district,  is  now  idle.  It  began  to  produce 
ibout  fourteen  years  ago  and  was  worked  for  about  eight  years,  during  which  period  it 
fielded  about  half  a  million  dollars  in  dividends  besides  paying  the  expenses  of  mine  devei- 
)pment,  the  building  of  a  200-ton  mill,  and  the  construction  of  about  15  miles  of  mountain 
oad.  The  closing  of  the  mine  was  due  to  the  enactment  of  a  State  law  which  requires  that 
very  mine  shall  have  two  openings.  It  has  now  been  determined  to  comply  with  (his  law 
)y  the  construction  on  the  1,500-foot  level  of  a  tunnel  which  will  be  over  a  mile  in  length. 
a  Visited  and  described  by  Mr.  Calkins. 
