Cushetunk Mountain in central New Jersey is a distinctive horseshoe-shaped ridge whose enclosed valley is now filled by Round Valley Reservoir. Long before European settlement, it lay within the homeland of Unami-speaking Lenape, especially the Musconetcongs, and its name comes from a Lenape word usually interpreted as “place of hogs.” Geologically, it formed about 200 million years ago when molten diabase intruded into older rock in the Newark Basin as Pangaea began to break apart, creating its unusual ring-like form. Its varied slopes and outcrops support diverse habitats, while the mountain and reservoir now serve as both a major regional water supply and a popular recreation area.