THE  HARTVILLE  IRON-ORE  RANGE,  WYOMING 
By  Sydney  11 .  Ball. 
INTRODUCTION. 
Iii  the  summer  of  L906  the  writer  spenl  three  months  in  studying 
the  geology  and  the  iron-on-  deposits  of  the  Hartville,  Wyo.,  iron 
range.  The  following  preliminary  description  of  the  results  of  the 
work  will  be  followed  in  the  near  future  by  a  more  extended  article* 
accompanied  by  adequate  maps.  Some  of  the  conclusions  here  stated 
may  be  modified  by  a  more  detailed  study  of  collections  and  notes. 
The  writer  wishes  gratefully  to  acknowledge  his  indebtedness  to 
Supt.  Louis  B.  Weed.  Engineer  George  C.  Botsford,  and  Capt.  Thomas 
Tucker,  of  t  he  Colorado  Fuel  and  Iron  Company ;  to  Mr.  C.  A.  Guern- 
sey, of  Guernsey,  and  to  Messrs.  Lauck  &  Stein,  of  Frederick. 
The  literal  lire  concerning  t  he  iron  of  i  lie  1  Earl  ville  range  is  summa- 
rized in  the  following  bibliography: 
Ricketts,  Loi  i-  l>..  Ann.  Rept.  Territorial  Geologist  to  the  Governor  of  Wyoming, 
Jan.,  l^ss.  Cheyenne,  Wyo.,  pp.  <>i  68.  Briefly  describes  the  geology  and  men- 
tions the  presence  of  large  bodies  of  iron  ore  near  Sunrise. 
Ricketts,  Loi  es  !>..  Ann.  Rept.  Territorial  Geologist  to  the  Governor  of  Wyoming, 
Jan..  L890,  Cheyenne,  Wyo.,  |>]>.  51  61.  Briefly  describes  the  geology  and  reports 
upon  the  ore  deposits  in  considerable  detail,  dividing  them  into  three  classes: 
(1)  Lenticular  masses  between  walls  in  crystalline  slates,  (2)  stratified  deposits 
at  the  base  of  the  cap  rock  Guernsey  formation),  and  (3)  residual  deposits.  Ee 
describes  in  detail  the  development  of  the  Sunrise  mine  and  the  presence  of  ore 
in  a  Dumber  of  other  claims  in  the  Dear  vicinity,  and  from  its  trend  infers  i hat 
the  ore  of  the  Chicago  claim  is  an  extension  of  the  Sunrise  deposit.  Il<'  gives  a 
number  of  analyses  of  iron  ore,  all  of  which  are  Dotably  high  in  iron  and  low  in 
phosphorus  and  silica. 
Km  (.n  i ',  \\  iii;  i  i:  I '..  Bull.  14,  "Wyoming  Experimenl  Station,  University  of  Wyoming, 
Laramie,  Wyo.,  Oct.,  L893,  pp.  176   177. 
Snow.  E.  P.,  Eng.  and  Mm.  Jour.,  vol.  60,  pp.  320-321,  1895.  General  description. 
Mentions  mining  by  the  Indians.     Estimates  ore  in  sigh.1  al  10. ()()(). 000  ions. 
Chance,  II.  M.,  The  iron  mines  of  Eartville,  Wyoming:  Trims.  Am.  [nst.  Min. 
Eng.,  vol.  30,  pp.  !'s7  ion:;.  In  this  excellenl  report  Mr.  Chance  describes  the 
original  pre-Cambrian  lenses  of  ore,  as  well  as  the  deposits  at  the  base  of  the 
Guernsey,  and  in  addition  placer  and  residual  deposits.  Ee  gives  a  Dumber  of 
analyses  of  the  ores.  Mr.  Chance's  work  is  of  greal  value,  since  he  records  the 
conditions  in  many  shafts  now  inaccessible.  This  paper  is  accompanied  by  a 
map  showing  the  location  of  the  principal  mines  and  prospects, 
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