The Kittatinny Valley lies to the east of Kittatinny Mountain and ends with the Highlands in the east. It is largely a region of rolling hills and flat valley floors. Elevations in this valley range from 400 to 1,000 feet.: It is part of the Great Appalachian Valley running from eastern Canada to northern Alabama. This valley is shared by three major watersheds—the Wallkill River, with its tributaries Pochuck Creek and Papakating Creek flowing north; and the Paulins Kill watershed and Pequest River watershed flowing southwest. This valley floor consists of shale and slate (part of the Ordovician Martinsburg Formation) and of limestone (part of the Jacksonburg Formation). Several parties have argued about the possibility of natural gas extraction in the region's Martinsburg and Utica shale formations, similar to the Marcellus Shale formations to the West in Pennsylvania and New York. Of special interest is Rutan Hill, a 440-million-year-old patch of igneous rock known as nepheline syenite. This site, north of Beemerville in Wantage Township, was once an ancient volcano—the only extant dormant volcano sites in the state.