Hilliard Shale  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Mesozoic
 ...Cretaceous
 ....Upper Cretaceous
 .....Hilliard Shale
RTUtah
 Wyoming
 Mesaverde Group
 Rock Springs Formation
SNNE Utah and SW Wyoming. Overlies Frontier Formation; underlies Adaville Formation, Blair Formation. Sometimes replaces Blair Formation and/or intertongues with overlying Rock Springs Formation or undifferentiated Mesaverde Group. Added to Thesaurus in 198