NICKEL    DEPOSITS    OF    NICKEL    MOUNTAIN,  OREGON.  121 
Ledoux,  A.  R.,  Notes  on  the  Oregon  nickel  prospects:  Canadian  Min.  Rev.,  vol.  20, 
1901,  pp.  84-85;  Jour.  Canadian  Min.  Ins!.,  vol.  4,  1901,  pp.  !SI    L89. 
Describes  the  geologic  relations  of  the  ore  bodies  and  gives  a  chemical  analysis 
of  the  ore. 
GEOGRAPHY   AND   HISTORY. 
Nickel  Mountain  is  one  of  many  peaks  and  ridges  of  moderate 
elevation  near  the  northeastern  base  of  the  Klamath  Mountains 
in  southwestern  Oregon.  It  is  about  3h  miles  west  of  Riddles,  a 
small  village  on  the  Southern  Pacific  Railroad,  about  225  miles 
south  of  Portland.  Riddles  is  713  feet  above  sea  level,  and  the 
highest  point  of  Nickel  Mountain  is  3,513  feet  above  sea  level.  The 
nickel  silicates  are  known  to  occur  only  on  the  southern  slope  of  the 
mountain,  above  an  elevation  of  2,000  feet.  A  good  wagon  road 
about  7  miles  in  length  runs  from  the  village  to  a  point  within  200  feet 
of  the  summit  of  the  mountain.  All  the  important  prospects  are 
reached  by  this  road. 
Although  these  deposits  were  discovered  about  1864,  their  true 
nature  was  not  recognized  until  1881.  Soon  after  that  time,  under 
the  management  of  W.  Q.  Brown,  the  original  own^r,  development 
work  was  commenced,  being  continued  in  greater  or  less  degree  until 
1900,  when  all  work  was  suspended.  Numerous  surface  openings 
were  made,  shafts  sunk,  and  tunnels  run.  The  longest  tunnel,  320 
feet  in  length,  was  completed  in  1897  by  the  Oregon  Nickel  Mines 
Company.  The  deepest  shaft,  83  feet  deep,  was  sunk  by  the  same 
company  about  the  same  time.  In  all,  there  are  more  than  600 
feet  of  tunneling.  Owing  to  the  caving  in  of  the  walls,  many  of 
these  workings  are  not  now.  accessible  except  at  the  entrances.  It 
is  estimated  that  between  3,000  and  4,000  tons  of  material  wTere 
taken  from  the  various  openings  and  placed  on  the  dumps,  where 
it  still  remains,  much  of  it  considerably  leached  and  of  low  grade, 
the  nickel  minerals  having  been  dissolved  and  carried  away.  Only 
a  few  small  shipments  of  ore  were  ever  made  to  the  smelters,  and 
these  merely  for  experimental  purposes.  In  1893  the  International 
Mining  Company  shipped  considerable  smelting  machinery  to  Riddles, 
but  it  was  never  used.  About  the  same  time  this  company  also 
erected,  near  the  deposits,  a  brick  engine  and  boiler  house,  a  sawmill, 
a  carpenter  shop,  a  blacksmith  shop,  and  other  buildings,  all  of  which 
are  now  in  a  more  or  less  dilapidated  condition. 
GEOLOGY. 
The  nickel  deposits  are  associated  with  saxonite  or  harzburgite,  a 
variety  of  peridotite,  a  basic  igneous  rock  consisting  chiefly  of  olivine 
and  enstatite.     Olivine  constitutes  more  than  two-thirds  of  the  whole 
