It is used as a means of transport by the illegal loggers. From the mountains, the illegal loggers float the troso (lumber) and float them downstream up to the ocean. During the late 20th century (and continuing up to the present), it has been the site of several clashes between the army and the communist group, the New People's Army. Recently, the government has made a project to link the Pacific Ocean with Angat River in Bulacan's mountains through a tunnel that will traverse Umiray River then cut through the mountains of Sierra Madre straight to Angat River. This project will alleviate the water shortages of both Bulacan province and Metro Manila. Species of shrimp and fish can be found here.