Yakima Basalt  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Neogene
 ....Miocene
 .....Yakima Basalt
RTIdaho
 Washington
 Oregon
 lower Pliocene
 upper Miocene
 Columbia River Basalt Group
 Grande Ronde Basalt
 Saddle Mountains Basalt
 Wanapum Basalt
SNUpper Miocene. Formerly also included in lower Pliocene? Typical plateau basalt. In E Washington; also in Oregon and Idaho. Sometimes called the Yakima Basalt Subgroup of the Columbia River Basalt Group, it has been considered to have as members, the Wana