The Pantabangan-Carranglan Watershed Forest Reserve is a conservation area located in the upper reaches of the Pampanga River in Nueva Ecija, Philippines, and borders the Sierra Madre and Caraballo Mountains in Aurora and Nueva Vizcaya. It encompasses of the drainage basin surrounding the Pantabangan Lake, an impoundment of the Pampanga River by the Pantabangan Dam. The multi-purpose dam is situated at the confluence of Pampanga River's two headwaters, namely the Pantabangan and Carranglan Rivers in the municipality of Pantabangan. It stretches above the dam site for to where Carranglan River originates in the Caraballo on the north, and for to where Pantabangan River originates in the Sierra Madre on the east. It is considered a critical watershed for the agricultural economy and hydroelectric power generation in the region of Central Luzon.