270  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  11)04.         [bull.  260. 
lead,  which  occurred  as  galena  with  a  quartz  gangue.  More  recently 
blende  associated  with  fluorspar  is  found  to  come  in  below  the  galena 
and  has  been  proved  to  a  depth  of  about  200  feet.  At  present  a  dry 
concentration  plant  is  being  erected,  with  the  expectation  of  being 
able  to  treat  the  ores. 
ZINC    RESOURCES    OF    THE    ROCKY    MOUNTAIN    STATES. 
The  zinc  resources  of  the  Western  States  are  as  yet  largely  uncle 
veloped.  Only  in  the  last  few  years  has  any  considerable  attention 
been  devoted  to  them,  and  in  1003  for  the  first  time  spelter  was 
locally  manufactured.  Prior  to  that  ore  had  been  shipped  both 
abroad  and  to  the  Kansas  smelters  and  a  limited  quantity  had  been 
burned  to  oxide  at  Canyon,  Colo.  The  building  of  a  smelting  plan! 
at  Pueblo  and  the  enlargement  of  the  oxide  plant  at  Canyon  has 
greatly  stimulated  the  Colorado  production  and  had  some  influence 
upon  that  of  Utah.  At  the  same  time  the  close  affiliation  of  the 
Ozark  Oxide  Company  with  the  carbonate  mining  companies  oper- 
ating in  the  Magdalena  Mountains  has  resulted  in  an  increased 
production  from  that  territory.  Plans  are  said  to  be  under  way 
for  the  utilization  of  the  zinc  found  in  the  Alice  mine  at  Butte,  Mont., 
and  at  various  other  points  in  the  West  the  attempt  is  being  made  to 
mine  zinc  ores. 
Colorado. — The  following  estimates  of  the  Colorado  production 
for  1904  are  quoted  by  the  Lead  and  Zinc  News: 
Colorado  zinc-ore  prod  net  ion  in  1904,  by  counties. 
Short  tons. 
Lake    105,000 
Summit    11,000 
Mineral    9.700 
Clear   Creek 7,000 
San    Juan '_ 3.  000 
Dolores     1.000 
Hinsdale    125 
Gunnison    100  , 
Saguache  50 
Chaffee  25 
Total VM.  (»(»<) 
These  figures  are  approximations  only,  but  represent  the  best  avail- 
able information.  The  ore  is  of  lower  grade  than  that  mined  at 
Joplin.  It  would  probably  be  safe  to  assume  an  average  content  of 
25  per  cent  metallic  zinc. 
The  zinc-producing  localities  in  Colorado  are  in  the  main  the  same 
as  those  yielding  lead,  and  have  already  been  discussed.  Pitkin 
County,  which  is  second  in  lead  production,  ships  no  zinc.     The  zinc 
