Organ Rock Formation Organ Rock Formation The Organ Rock Formation or Organ Rock Shale is a formation within the late Pennsylvanian to early Permian Cutler Group and is deposited across southeastern Utah, northwestern New Mexico, and northeastern Arizona. This formation notably outcrops around Canyonlands National Park, Natural Bridges National Monument, and Monument Valley. The age of the Organ Rock is constrained to the latter half of the Cisuralian Epoch by age dates from overlying and underlying formations. Important early terrestrial vertebrate fossils have been recovered from this formation in northern Arizona, southern Utah, and northern New Mexico. These include the iconic Permian terrestrial
Devil's Backbone (rock formation) Devil's Backbone (rock formation) Devil's Backbone is a rock formation and peninsula formed by the flow of Fourteen Mile Creek into the Ohio River, and is currently situated in Charlestown State Park near Charlestown, Indiana and across the Ohio River from Louisville, Kentucky. According to local legend, on this bedrock ridge once stood a stone fortress that was built by Welsh explorers led by Prince Madoc sometime in the 12th century. The Backbone is believed to have been formed by the processes of glaciation where a combination of ice sheet advances, meltwater flows and a diversion of the Ohio River