GOLD    IN    UINTA    COUNTY,   WYO.,  AND    ON    SNAKE    RIVER.  87 
Two  or  three  enterprises  now  on  foot  at  different  points  along  the 
Snake  River  will  test  the  problem  of  saving  the  possible  by-products 
of  the  gravels  in  addition  to  the  gold  content.  One  of  these  is  being 
undertaken  at  a  point  on  the  Oregon  side  of  the  river  a  short  distance 
below  Weiser,  Idaho,  and  another  at  a  point  a  short  distance  above 
American  Falls,  Idaho.  The  results  of  these  efforts  will  be  watched 
with  much  interest,  for,  if  any  margin  of  profit  at  all  can  be  made  in 
which  platinum  becomes  an  important  factor  in  the  output,  it  will  be 
important  to  the  country  at  large,  as  the  business  might  be  greatly 
extended,  since  there  are  billions  of  yards  of  these  low-grade  gold  and 
platinum-bearing  gravels  along  the  banks  of  Snake  River.  The  por- 
tion of  Snake  River  below  the  Grand  Canyon  that  flows  through 
Bingham,  Blaine,  Oneida,  Cassia,  and  Lincoln  counties,  Idaho,  yielded 
in  1905  approximately  1,300  fine  ounces  of  gold,  valued  at  a  little  more 
than  $26,000. 
PLATINUM   IN   THE   SNAKE   RIVER  AURIFEROUS   GRAVELS. 
The  recent  experiments  of  David  T.  Day,  of  the  United  States  Geo- 
logical Survey,  at  Portland,  Oreg.,  on  the  heavy  placer  concentrates  of 
the  Pacific  slope,  to  determine  their  value  in  other  metals  and  min- 
erals besides  gold,  included  a  number  of  samples  of  Snake  River  con- 
centrates, nearly  all  of  which  yielded  from  a  trace  to  an  appreciable 
amount  of  platinum,  but  Doctor  Day  doubts  whether  many  of  the 
results  were  obtained  from  representative  samples.  The  subject  is 
interesting  and  well  worthy  of  close  and  intelligent  investigation. 
It  may  prove,  however,  that  under  the  present  state  of  the  platinum 
market,  the  platinum  values  are  too  thinly  scattered  along  this  stream 
to  be  of  much  value  unless  they  are  combined  with  the  concentrates 
and  have  largely  passed  unnoticed.  The  actual  contents  of  magnetite 
and  similar  heavy  residues  in  these  gravel  beds,  as  nearly  as  has  been 
determined,  is  from  one-fourth  to  one-third  of  1  percent  of  the  gravel, 
and  when  their  visible  free-gold  content  is  properly  amalgamated  out 
the  residue  will  not  assay  over  $5  in  gold  per  ton. 
During  the  past  year  Robert  N.  Bell,  State  mine  inspector  of  Idaho, 
visited  the  point  on  Snake  River  from  which  the  highest  results  in 
platinum  were  reported  during  the  progress  of  the  Portland  fair.  A 
sample  taken  at  this  point  yielded  platinum  at  the  rate  of  eighteen 
one-hundred ths  of  an  ounce  per  ton  and  several  hundred  dollars  in 
gold  per  ton.  Air.  Bell  learned  that  the  sample  was  selected  from  the 
first  burlap  on  one  of  the  " machine"  tables,  with  the  fine  gold  left  in, 
and  probably  represented  a  concentration  of  several  thousand  to  one. 
A  subsequent  sample  of  clean  black  concentrates  taken  from  below 
the  grinding  pan,  after  the  free  gold  had  been  amalgamated  out,  was 
sent  to  Doctor  Day  and  gave  a  result  of  $3  gold  per  ton  and  only  a 
trace  of  platinum. 
