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
Acadia Cliffs State Nature Preserve The name derives from the fact that the land was formerly owned by the Acadia Coal Company. The property includes an old millstone quarry, and many old millstones can still be seen on the site, now back in the forest. This nature preserve was established in part to protect the Bradley's spleenwort, "Asplenium bradleyi", which grows there. The spleenwort is a state-listed plant species. Acadia Cliffs State Nature Preserve Acadia Cliffs State Nature Preserve is a state nature preserve in Washington County, Ohio, United States, with a small neck extending into Athens County, Ohio. Covering an area of , it