INTRUSIVE IGNEOUS ROCKS--Felsic and mafic igneous bodies; the larger are mainly felsic.  Ti

  THOROFARE CREEK GROUP (AGE 44 TO 49 Ma)--Light-colored volcaniclastic strata,
       andesite lava flows, and dark-brown breccia.  Tts
     Wiggins Formation (age 44-47 Ma)--Light-gray volcanic conglomerate and white tuff,
       containing clasts of igneous rocks.  Twi
     Two Ocean and Langford Formations (age 47-48 Ma)--Dark-colored andesitic
       volcaniclastic rocks and flows underlain by light-colored andesitic tuffs and flows.  
       Ttl,Tts 
     Tepee Trail Formation (age probably about 48 Ma)--Green and olive-drab hard general-
       ly well bedded andesitic conglomerate, sandstone, and claystone.  Tt
     Aycross Formation (age 49 Ma)--Brightly variegated bentonitic claystone and
       tuffaceous sandstone, grading laterally into greenish-gray sandstone and claystone.
       In and east of Jackson Hole contains gold-bearing lenticular quartzite
       conglomerate.  Ta
  SUNLIGHT GROUP.  Ts, Tts
     Trout Peak Trachyandesite.  Ttp, Ttl, Tts, Ts
     Wapiti Formation--Andesitic volcaniclastic rocks.  Twp, Tts, Ts
     Crescent Hill Basalt.  Ts
     Mount Wallace Formation--Felsic and mafic volcaniclastic rocks.  Ts
  HOMINY PEAK FORMATION (AGE ABOUT 49 Ma)--Mafic volcaniclastic conglomerate and tuff; 
       sparse claystone in upper part; gold-bearing quartzite conglomerate at base. Thp 
  WASHBURN GROUP.  Taw
     Sepulcher Formation--Andesitic and dacitic volcaniclastic rocks.  Taw
     Lamar River Formation--Andesitic lava and volcaniclastic rocks.  Taw
     Cathedral Cliffs Formation--Light-colored andesitic volcaniclastic rocks. Taw