Keefer Sandstone  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Silurian
 ....Middle Silurian
 .....Keefer Sandstone
RTPennsylvania
 Maryland
 West Virginia
 Clinton Group
 Rochester Formation
SNIn Clinton Group. W Maryland, and from central Pennsylvania to NE West Virginia.