Abra River is the 6th largest river system in the Philippines in terms of watershed size. It has an estimated drainage area of 5,125 square kilometers and a length of 178 kilometers from its source in the vicinity of Mount Data in the Benguet province.
The Abra river originates from the southern section of Mount Data. It descends westward to Cervantes, Ilocos Sur and flows to the province of Abra. At a point near the municipality of Dolores, it is joined by the Tineg river, which originates from the uplands of Abra.