The Dominican Republic is generally mountainous, with deserts in the extreme western regions. The principal mountain range, the Central Cordillera, running from east to west and extensively pine-forested, bisects the republic. Between the Central Cordillera and the Northern Cordillera (and their associated plains) lies the famous Cibao (La Vega Real) Valley (225 km/140 mi long, with an average width of 23 km/14 mi), noted for the excellent quality of its soil. Fertile valleys also abound in the central and eastern areas. The country contains both the highest mountain in the West Indies, Mt. Duarte (Pico Duarte, 3,175 m/10,417 ft), and the lowest-lying lake, Lake Enriquillo (46 m/151 ft below sea level). The Yaque del Norte, the Yaque del Sur, and the Yuna are the principal rivers.