Belt Supergroup  search
BTChronostratigraphic Units
 .Precambrian
 ..Proterozoic
 ...Mesoproterozoic
 ....Belt Supergroup
RTIdaho
 Montana
 British Columbia
 Altyn Limestone
 Aldridge Formation
 Ravalli Group
 Bonner Formation
 Disturbed Belt
 Empire Formation
 Helena Formation
 Missoula Group
 Mount Shields Formation
 Newland Limestone
 Prichard Formation
 Revett Quartzite
 Saint Regis Form
SNComprises Piegan Group, Missoula Group, and Ravalli Group.