Title: Map of the Mercer clay and adjacent units in Clearfield, Centre, and Clinton Counties, Pennsylvania /
Authors: Pennsylvania.; Williams and Heintz Map Corporation
Publisher: Pennsylvania Bureau of Topographic and Geologic Survey,
Year: 1964
Subjects: Geology Pennsylvania Clearfield County Maps.; Geology Pennsylvania Centre County Maps.; Geology Pennsylvania Clinton County Maps.; Geology; Pennsylvania Centre County; Pennsylvania Clearfield County; Pennsylvania Clinton County