Lance Formation  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Mesozoic
 ...Cretaceous
 ....Upper Cretaceous
 .....Lance Formation
RTWyoming
 Montana
 Colorado
 North Dakota
 South Dakota
SNIncludes Colgate Sandstone Member, Cannonball Marine Member, Ludlow Lignitic Member, Tullock Member, Hell Creek Member, Torrington Member, and Ilo Ridge Member. Montana, W North Dakota, W South Dakota, and Wyoming.