Ilagan River

The Ilagan River, also known as the Pinacanauan de Ilagan River,^[2] is a river in the province of Isabela, Cagayan Valley, Philippines. It is one of the major tributaries of the Cagayan River, the largest river in the Philippines. The Ilagan River originates from the western slopes of the Sierra Madre and drains the eastern central portion of the Cagayan River basin. It has an estimated catchment basin size of 3,132 square kilometres (1,209 sq mi)^[3] and an estimated annual discharge of 9,455 million cubic meters/s. It flows westward and joins the Cagayan River in Ilagan, Isabela.^[1]

Ilagan River
The Ilagan River as it passes through the municipalities of San Mariano (background) and Benito Soliven (foreground).
Ilagan River mouth Show map of Luzon Ilagan River (Philippines) Show map of Philippines
Native name	Pinacauan De Ilagan (Ilocano)
Location
Country	Philippines
Region	Cagayan Valley
Province	Isabela
Physical characteristics
Source	Sierra Madre mountains
• location	Casiguran, Aurora, Central Luzon
• coordinates	16°18′42″N 121°59′6″E
Mouth	Cagayan River
• location	Ilagan, Isabela
• coordinates	17°10′03″N 121°53′25″E
Length	189 km (117 mi)
Basin size	3,132 km2 (1,209 sq mi)
Discharge
• average	270 m3/s (9,500 cu ft/s)[1]
Basin features
Progression	Ilagan River – Cagayan River
Tributaries
• right	Abuan River Bintacan River

Tributaries

The Ilagan River at Ilagan

The major tributaries of Ilagan River are:

• Abuan River – originates from the mountains of the Northern Sierra Madre Natural Park where one of the widest tropical rainforests in Luzon can be found.
• Bintacan River