Lago Puelo is a stunning glacial lake nestled within Lago Puelo National Park in the northwest corner of Chubut Province, Patagonia, Argentina, at approximately 200 meters above sea level. The lake sits at coordinates 42°11′S 71°41′W and is surrounded by the lush Valdivian rainforest, one of the most biodiverse temperate forest ecosystems in the Southern Hemisphere. The park covers 276.74 square kilometers and was established as an independent national park in 1971, originally created as an annex to the nearby Los Alerces National Park. The lake's waters are famously crystal clear with a striking blue-green color, and the surrounding landscape features dense forests of coihue, lenga, arrayán, and ciprés de la cordillera. The lake enjoys an unusually mild microclimate for the Patagonian Andes, and summer water temperatures can reach as high as 20°C (68°F), making it one of the warmer mountain lakes in the region. The Río Puelo originates from the lake's outlet, flowing westward toward Chile, and the lake itself sits at the intersection of the Argentine and Chilean border zones, adding a unique geographic character to any fishing excursion here.