The Merlo River is a river located in the province of San Luis, Argentina. It flows through the picturesque region of the Sierra de los Comechingones, known for its stunning landscapes and natural beauty. The river is a popular spot for outdoor activities such as fishing, hiking, and camping, attracting both locals and tourists. The Merlo River is a tributary of the Rio Conlara, which eventually joins the Rio Quinto. The river's clear waters and surrounding greenery provide a habitat for various wildlife species. Its importance to the local ecosystem and recreational opportunities makes it a significant natural feature in the area.