VOLCANIC    ASH BIBLIOGRAPHY.  479 
Peale,  A.  C.    Three  Forks  area,  Mont.    Geologic  Atlas  U.  S.,  folio  24,  U.  S.  Geol.  Survey,  1886,  p.  5. 
Haworth,  F.  M.     Geological  survey  of  Kansas,  vol.  2,  1897,  pp.  256-257. 
Barbour,  E.  H.  The  deposits  of  volcanic  ash  in  Nebraska.  Ann.  Rept.  State.  Board  of  Agriculture, 
189G,  pp.  232-238. 
Barbour,  E.  H.  Notes  on  the  ash  beds  of  Nebraska  and  the  Great  Plains.  Mineral  Industry,  vol.  6, 
1898,  pp.  22-25. 
Darton,  N.  H.  Geology  and  water  resources  of  Nebraska  west  of  the  one  hundred  and  third  merid- 
ian.    Prof.  Taper  U.  S.  Geol.  Survey  No.  17,  1903,  pp.  42-43. 
Darton,  N.  II.     Oelrichs  district,  South  Dakota.     Geologic  Atlas  U.  S.,  folio  85,  U.  S.  Geol.  Survey, 
1902,  p.  6. 
Darton,  N.  II.    Camp  Clark  district,  Nebraska.     Geologic  Atlas  U.  S.,  folio  87,  U.  S.  Geol.  Survey, 
1903,  p.  4. 
DARTON,  N.  H.     Scotts  Bluff  district,  Nebraska.     Geologic  Altas  U.  S.,  folio  88,  U.  S.  Geol.  Survey, 
1903,  p.  5. 
Rowe,  J.  P.    Some  volcanic  ash  beds  in  Montana.    Bull.  Univ.  Montana  No.  17,  1903. 
