Lago Ranco is a stunning glacial lake nestled in the Ranco Province of the Los Ríos Region in southern Chile, recognized as the largest lake in the region and the fourth largest in the entire country. Covering an impressive 442 km² with a maximum length of 26 km and maximum width of 21 km, this deep, crystalline body of water sits flanked by the Cordillera de la Costa and the Andes Mountains, creating a dramatic and picturesque setting that draws anglers from across Chile and beyond. The lake drains into the Río Bueno and receives inflows from several notable rivers including the Río Calcurrupe, Río Nilahue, Río Caunahue, and Río Riñinahue — each of which offers its own fishing opportunities. With an average depth of 122 m (400 ft) and a maximum depth of 199 m (653 ft), Lago Ranco is a naturally oligotrophic system with exceptionally clear water, making it one of the most visually striking and productive sport fishing destinations in Patagonian Chile. The lake features approximately 25 islands and islets, adding structural complexity to the fishery. The town of Lago Ranco, founded in 1941, sits along the shoreline and serves as a hub for visiting anglers, with much of the local tourism economy built around fly fishing services, lodges, and guiding operations.