The Nimba Range is a narrow ridge extending approximately 40 km long, with an orientation of northeast-southwest; it forms a part of the southern extent of the Guinea Highlands. Its highest peak is Mount Richard-Molard at 1,752 m (5,750 ft). Other peaks include Grand Rochers at 1694 m (5558 ft), Mont Sempéré at 1682 m (5518 ft), Mont Piérré Richaud at 1670 m (5479 ft), Mont Tô at 1675 m (5495 ft), and Mont LeClerc 1577 m (5174 ft). All of them are located in the Guinean part of the reserve. There are about fifty springs, including the origins of the Cavally, Cestos, and Sassandra Rivers. Mining of top-quality iron-ore poses the major threat to the unique geomorphology and wildlife.