Kittatinny Mountains, Sussex County, NJ

The forest is underlain by two major geologic formations, both dating back about 400 million years.

1. Eastern Section

Consists of Shawangunk conglomerate, a mixture of white quartz and reddish slate pebbles embedded in a grayish silicate matrix. The conglomerate, sometimes called "pudding stone," forms the crest of Kittatinny Mountain and its steep rocky southeastern slope. Excellent examples of the conglomerate can be observed along the Appalachian Trail, which leads to the summit of Sunrise Mountain. (A Guide to Stokes State Forest, p2)

2. Western Section

West of the ridge crest the forest sits upon the High Falls formation, consisting of alternating red-green and olive colored sandstones and shales. In the higher elevations the softer red shales predominate, with the top layer being concealed by varying thicknesses of glacial till. The lower beds of the High Falls formation contain red quartzitic sandstones. Transition from the Shawangunk to the High Falls is not sharply defined but occurs very gradually. Excellent examples of the High Falls formation can be observed in the rock outcrops along Coursen Road and in Tillman Ravine.