During Jurassic times, 150 million years ago, this area enjoyed a humid, temperate climate with flourishing forests, but intense volcanic activity buried them in ash. Erosion later exposed the mineralized Proaraucaria trees (ancestors of the modern araucaria, unique to the southern hemisphere), up to 3m in diameter and 35m in length. Today the 150-sq-km Monumento Natural Bosques Petrificados has a small visitor center, English-language brochure and short interpretive trail, leading from park headquarters to the largest concentration of petrified trees.
Until its legal protection in 1954, the area was plundered for some of its finest specimens; please don’t perpetuate this unsavory tradition.
The park is 157km southwest of Caleta Olivia, accessed from the good gravel RP 49, leading 50km west from a turnoff at Km2074 on RN 3. There’s no public transportation. Buses from Caleta Olivia leave visitors at the junction, but you may have to wait several hours for a lift into the park. Los Vikingos runs tours from Puerto Deseado.
There’s basic camping and provisions at La Paloma, 20km before park headquarters. Camping in the park is prohibited.