Columbia River Basalt  search
USEColumbia River Basalt Group
Columbia River Basalt Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Neogene
 ....Miocene
 .....Columbia River Basalt Group
UFColumbia River Basalt
RTPliocene
 Idaho
 Washington
 Oregon
 Picture Gorge Basalt
 Yakima fold belt
 Frenchman Springs Member
 Grande Ronde Basalt
 Saddle Mountains Basalt
 Wanapum Basalt
 Yakima Basalt
SNMiocene. The Columbia River Basalt was formerly also considered Pliocene (?). N Idaho, Oregon, and Washington. Has been divided into the Yakima Basalt (subgroup) containing the Wanapum Basalt, the Grande Ronde Basalt, and the Saddle Mountains Basalt; and