Bisti/De-Na-Zin Wilderness

The Bisti/De-Na-Zin Wilderness is a 45,000-acre badlands area in San Juan County, New Mexico, managed by the Bureau of Land Management and considered the most accessible badlands in the San Juan Basin. Its landscape is built from four tilted geological layers, the Fruitland, Kirtland, Ojo Alamo and Nacimiento formations, laid down as the Western Interior Seaway repeatedly flooded and retreated across the region during the Late Cretaceous; when the sea finally withdrew about 74 million years ago it left behind deltaic and floodplain sediments. The badlands themselves are geologically young, carved by erosion only within roughly the last 2.8 to 5.6 million years. The wilderness is known for its hoodoos, tall narrow rock spires that survive where a resistant cap of harder rock protects a softer pinnacle underneath from wearing away, and it also holds extensive fossil beds spanning the Cretaceous-Paleogene boundary. This entity documents the Bisti/De-Na-Zin Wilderness specifically as a geological formation.