The Rio Rapel is a significant river system in Chile's O'Higgins Region, formed at the confluence of the Cachapoal River and the Tinguiririca River at a point known as La Junta. This meeting of two major river systems creates a waterway with a substantial drainage basin of approximately 13,695 square kilometers (5,288 square miles). The river is perhaps best known today for the Rapel Dam, which impounds the upper portion of the river to form Lago Rapel — a large artificial reservoir that has become a popular destination for boating, water sports, fishing, and tourism. Below the dam, the Rio Rapel continues its course before eventually reaching its mouth at the Rio Grande. The combination of the reservoir environment and the tailwater section below the dam offers anglers a diverse range of fishing opportunities within a scenic landscape characteristic of central Chile.