It originates from the Cordillera mountains and traverses the provinces of Benguet, La Union, and Ilocos Sur, with a total length of 96 km (60 mi), emptying into the South China Sea.

The river serves as the boundary between the provinces of Ilocos Sur and La Union.

[2][3] The river's headwaters are a confluence of smaller creeks along the south of barangay Lubo, in Kibungan.

Several other tributary creeks merge with the river as it flows along Atok and Kapangan.

With the aid of young women from a neighboring village, he undertook the task of removing the contaminants, consisting of soil and blood, that had fouled the river's waters, resulting in the demise of aquatic life within its ecosystem.