MORRISON FORMATION
  Northern Yellowstone area--Variegated silty claystone and fine-grained sandstone.  KJk
  North Wyoming--Dully variegated claystone, nodular limestone, and gray silty sandstone.
     In southern Yellowstone and Jackson Hole areas the Morrison is not certainly
     present.  KJ, KJs, KJg, K@, MzPz
  South Wyoming--Dully variegated claystone, nodular white limestone, and gray silty sand-
     stone.  KJ, KJs, MzPz
  Northeast Wyoming--Dully variegated siliceous claystone, nodular white limestone, and gray
     silty sandstone.  KJ