The Rio Grande de Mindanao, also known as the Mindanao River, is the second-largest river system in the Philippines. Located on the southern island of Mindanao, with a total drainage area of 23,169 km2 (8,946 sq mi),[2] draining the majority of the central and eastern portion of the island, and a total length of approximately 373 km (232 mi).[1][3] It is an important transportation artery, used mainly in transporting agricultural products and, formerly, timber.