The Río Grande de Arecibo is a river of Puerto Rico. The headwaters lie in the mountains to the south of Adjuntas. From there it flows north until it reaches the Atlantic Ocean near Arecibo. The tributaries lie along the side of the Cerro de Punta and the Utuado pluton. It flows through the northern, passing along a gorge that is 200 m deep and 800–1,200 m wide. It fl…The Río Grande de Arecibo is a river of Puerto Rico. The headwaters lie in the mountains to the south of Adjuntas. From there it flows north until it reaches the Atlantic Ocean near Arecibo. The tributaries lie along the side of the Cerro de Punta and the Utuado pluton. It flows through the northern, passing along a gorge that is 200 m deep and 800–1,200 m wide. It flows through the middle of Puerto Rico.