GALLATIN GROUP
  Snowy Range Formation--Medium-gray limestone and underlying greenish-gray shale.  O_
  Pilgrim Limestone--Blue-gray and yellow mottled hard limestone.  O_
GALLATIN LIMESTONE OR GROUP
  Thrust belt--Gray and tan limestone.  O_
  North Wyoming--Blue-gray and yellow mottled hard dense limestone.  O_, _r, Pzr