The Cave Location Map lists 142 caves in the following counties: Hunterdon, Morris, Somerset, Sussex, and Warren. It features locations of Precambrian Franklin Marble, Cambro Ordovician Kittatinny Limestones, Ordovician Jacksonburg Formations, and Silurian-Devonian Limestones. 63.5 x 48.3 cm Bulletin 70, Plate 1