Winnipeg Formation  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Ordovician
 ....Middle Ordovician
 .....Winnipeg Formation
RTSaskatchewan
 Montana
 North Dakota
 Manitoba
 South Dakota
SNDefined as the shale and sandstone section which underlies the limestone of Red River Formation and which rests upon Precambrian basement complex in Manitoba. Surface and subsurface in Manitoba, and subsurface in Saskatchewan; and subsurface in Montana, N