Ringold Formation  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Cenozoic
 ...Neogene
 ....Pliocene
 .....Ringold Formation
RTPleistocene
 Washington
 Oregon
SNPliocene. Previously considered middle and upper Pleistocene. NE Oregon and SE Washington. Added to Thesaurus in 1985.