Straddling the Carretera Austral beyond the Balmaceda turnoff, marking the divide between the Río Simpson and Río Ibáñez drainages, Reserva Nacional Cerro Castillo is a 179,550-hectare unit whose map boundaries look like jigsaw puzzle pieces. Its signature landmark is Cerro Castillo itself, whose soaring basaltic battlements, above the tree line, truly resemble a medieval castle.
Elevations range from about 500 meters to Cerro Castillo’s 2,320-meter summit, embellished by three south-facing glaciers. Like most of the region, it gets substantial rainfall and snow at higher altitudes, but some east-facing areas enjoy a rain-shadow effect.
Nearly pure stands of the southern beech lenga dominate the forest landscape up to about 1,200 meters, along with the related coigüe, ñire, and many shrubs. Steppe-like grasslands typify the rain-shadow areas.
Mammals include the puma, huemul, two fox species, and skunks. Birds are common, including the Andean condor, various owls, the austral blackbird or tordo, and the austral parakeet or cachaña.
About eight kilometers south of Laguna Chiguay, a faint westbound road from a crumbling construction camp is the starting point for Sendero Las Horquetas, a four-day backpack that climbs the valley of Estero la Lima to pass beneath the spires of Cerro Castillo before descending to the roadside village of Villa Cerro Castillo . This is easier from the north than from the south, where the approach is steeper and more rugged. For details, see Clem Lindenmayer’s Trekking in the Patagonian Andes (Lonely Planet, 2003) or Tim Burford’s Chile and Argentina: The Bradt Trekking Guide (2001).
At the reserve’s northeastern edge, Conaf’s woodsy Camping Laguna Chiguay (Km 67, US$4.50 per site) is just west of the highway. At the southern approach, there are simple accommodations at Villa Cerro Castillo , just outside the reserve boundary.
Conaf maintains a ranger station on the highway opposite the Laguna Chiguay campground.
All public transportation between Coyhaique , on the one hand, and Puerto Ibáñez and Villa Cerro Castillo on the other, passes through the reserve’s northern sector.