One of the Wahweap Hoodoos north of Big Water, Utah. Softer, white–buff-colored rock of the Middle Jurassic (~165 million year old) Entrada Sandstone is capped by harder, dark brown conglomerates of the Lower Cretaceous (~100 million year old) Naturita Formation. In general, the more durable (but not invulnerable!) Naturita protects the underlying Entrada from weathering. Isolated "islands" of Naturita (either fallen, eroded blocks or remnant outcrops) protect columns of underlying Entrada Sandstone, forming the mushroom-shaped hoodoos, which generally aren't very long lived. The rock outcrops and hoodoo are set against a grey sky.