68  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull. 225. 
CREEKS  AND   DEVELOPMENT. 
The  creeks  of  present  economic  importance  are  Pedro,  called  Gold 
Stream  below  the  point  where  Gilmore  enters  it,  and  Twin  Creek,  a 
tributary  of  Pedro;  Cleary  Creek,  with  its  tributaries,  Chatham  and 
Wolf;  and  Fairbanks  Creek.  They  are  but  a  few  miles  apart,  sepa- 
rated by  broad  divides,  1,000  feet  or  more  above  them,  and  flow  in 
divergent  courses — Pedro  toward  the  southwest  and  west,  Cleary 
toward  the  northwest,  Fairbanks  toward  the  east.  Pedro  and  Cleary 
belong  to  the  drainage  system  of  the  Chatanika,  which  lower  down  is 
called  the  Tolovana,  and  Fairbanks  Creek  flows  into  Fish  Creek,  a 
tributary  of  the  Little  Chena.  Cleary  and  Fairbanks  creeks  are 
easily  reached  by  comparatively  good  trails  from  Pedro  Creek.  The 
distance  is  about  6  miles  from  the  mouth  of  Twin  on  Pedro  to  Discov- 
ery Claim  on  Cleary  Creek,  and  it  is  about  the  same  to  the  head  of 
Fairbanks  Creek. 
Claims  include  20  acres,  are  a  quarter  of  a  mile  long,  and,  with  a  few 
exceptions,  are  staked  lengthwise  of  the  creeks. 
Pedro  Creek  and  its  tributaries. — Pedro  Creek  flows  in  an  open 
valley.  It  is  limited  on  the  east  by  a  rather  abrupt  slope,  and  on  the 
west  by  broad,  rounded  spurs,  sloping  gradually  from  the  divide  to 
the  stream  bottom,  and  occasionally  showing  a  bench-like  character  in 
the  vicinity  of  the  stream.  Toward  the  headwaters  and  along  the  tribu- 
taries the  sides  approach  until  the  valle}^  becomes  sharply  V-shaped. 
The  stream  flat  or  valley  floor  varies  in  width  up  to  a  maximum  of 
about  1,000  feet,  and  the  grade  in  the  portion  where  work  is  in  progress 
is  about  100  feet  to  the  mile.  The  stream  itself  carries  perhaps  3  to 
4  sluice  heads  of  water,  or  about  200  miner's  inches,  in  its  meandering 
course  over  the  willow-covered  flat.  The  sides  of  the  valle}7  are  clothed 
with  a  light  growth  of  spruce,  sufficient  only  for  wood  and  cabin  mate- 
rial. The  tributaries  are  small  and  flow  in  narrow  valleys.  On  the 
west  are  Dead  wood,  Twin,  and  Steamboat  creeks;  on  the  east,  Nugget 
Gulch,  California  Gulch,  and  Gilmore  Creek.  The  continuation  of 
Pedro  below  Gilmore  has,  unfortunately,  received  another  name  and 
is  known  as  Gold  Stream. 
The  area  of  present  interest  includes  the  lower  portion  of  Twin 
Creek,  the  3  miles  of  Pedro  from  Twin  to  Gilmore,  and  2  to  3  miles 
on  Gold  Stream. 
Twin  Creek  heads  in  the  triangular  divide  between  the  Fairbanks, 
Cleary,  and  Pedro  drainage  areas.  It  is  about  3  miles  in  length  and 
flows  in  a  narrow  V-shaped  valley  over  the  bed  rock,  composed,  so  far 
as  known,  of  quartzite-schist  and  porphyritic  granite.  The  creek 
was  staked  in  September,  1902.  Work  has  been  done  at  the  mouth 
and  at  a  point  about  one-half  mile  above  the  mouth. 
There  is  about  12  feet  of  material  on  the  bed  rock,  half  of  it  muck 
