Rio de Los Cipreses National Reserve is a nature reserve located in Machali, O'Higgins Region, Chile. It is named after Rio de Los Cipreses, a tributary of Cachapoal River and lies in one of the most glaciated areas of the Central Chile Andes. The reserve contains Valdivian temperate forests at lower elevations and Southern Andean steppe at higher elevations.
It also protects some of the northernmost stands of Austrocedrus chilensis. The reserve offers opportunities for mountain climbing. It is home to challenging mountains, including Palomo volcano, Alto de Los Arrieros and Cerro Dr. Hernán Cruz. River and gorge running through the center of the reserve.