Área protegida Valle Cretácico, Protected area in Río Negro Province, Argentina

The Área Protegida Valle Cretácico is a protected area in the El Cuy department of northwestern Río Negro Province, on the border with Neuquén. Created in 1996, it covers about 200,000 hectares of wind-eroded plateau, roughly 120 km north to south and 5 to 30 km wide, cut by canyons and gullies that expose Cretaceous sediments. Its cliffs and up-to-70-metre rock towers rise along the shore of the Ezequiel Ramos Mexía reservoir.

The protected area was created in 1996 to preserve the fossil sites and geological formations of the region. Decades of excavations have uncovered remains of major dinosaurs such as Giganotosaurus and Antarctosaurus.

The Cañadón de las Águilas is a narrow section of the area with colorful rock walls that visitors can walk through. Geologists and fossil enthusiasts from Argentina and abroad come regularly to study the exposed sediment layers up close.

The area is accessible via Provincial Route 74 and tracks connecting Cerro Policía and Loma Atravesada. Since the terrain is open and exposed, sturdy footwear and enough water are recommended, especially given the wind and dry conditions.

The area's name refers to the exposed strata laid down 90 to 100 million years ago, which also preserve fossils of conifers, ginkgos, palms and cycads. In 1925 the sauropod Antarctosaurus wichmannianus was found in Upper Cretaceous sediments here.