| This view is looking east down Little Ruin Canyon toward Sleeping Ute Mountain in the distance. The caprock of the canyon is a dense sandstone of the Dakota Formation of Late Cretaceous age (about 96 million years old; Dyman and others, 2002). The Dakota Formation (or Dakota Sandstone) also contains layers of mudstone and some soft coal. The Dakota Formation overlies the Burro Canyon Formation (late Early Cretaceous, about 100 million years old). The Burro Canyon Formation contains sandstone and conglomerate bearing pebbles and cobbles of chert, quartzite, and limestone. The Burro Canyon can be seen along road cut and outcrops along valleys in the park vicinity (Aubrey, 1992; NPS, 2010). |
