Frozen in time, the sweeping strata of ancient dunes catch a sprinkle of sunlight in the depths of the Paria drainage. Nearly 200 million years ago, winds of the Jurassic period deposited layers of sand, creating a thick blanket of cross-bedded dunes. Today, the fossilized dunes emerge as Navajo Sandstone. The canyons and mesas of the 112,500 acre Paria Canyon-Vermilion Cliffs Wilderness are spectacular exhibits of Navajo Sandstone, exposed and sculpted by eons of erosion.