Today new features are being formed as old ones are destroyed. Erosion and weathering work slowly but relentlessly, creating dynamic landforms that gradually change through time. Change sometimes occurs more dramatically. In 1991 a rock slab 60 feet long, 11 feet wide, and four feet thick fell from the underside of Landscape Arch, leaving behind an even thinner ribbon of rock. Delicate Arch, an isolated remnant of a bygone fin, stands on the brink of a canyon, with the dramatic La Sal Mountains as backdrop.
The rise and all of an arch ~~ like all living things, arches have life cycles too. Starting as small holes in rock faces, they enlarge and eventually collapse from weathering and erosion. Water, whether from rain or snow, dissolves the natural cement (calcium carbonate) in the Entrada sandstone. Sand grains once "glued" together are separated and washed away; arches form, grow, mature, and fall. Although there are no major arches here at Courthouse Towers, the cycle is continuing. Look for Baby Arch in the rock wall to the left of Sheep Rock. Weathering over time will enlarge this growing arch until it finally collapses. (See picture below.)
Sheep Rock is part of an eroding rock wall or "fin" that probably contained arches (above). We can't be certain, but the sharp cleavage found on Sheep Rock and the shapes of other rock faces near it are clues that an arch once connected the "sheep" to the rock mass it faces.
The forces of erosion are sculpting more than arches. Balanced Rock clearly shows the various layers responsible for this amazing defiance of gravity. The caprock of the hard Slick Rock Member (topmost stone) of the Entrada Sandstone is perched upon a pedestal of mudstone. This softer Dewey Bridge Member (the base) of the Carmel Formation weathers more quickly than the resistant rock above. Eventually, the faster-eroding Dewey Bridge will cause the collapse of Balanced Rock. Balanced Rock Formation is 128 feet high; boulder height is 55 feet, and it weighs 3,500 tons.
|Yes, those are people up there|
|Looks like a future arch|
These are considered the north and south windows.
|North Window and South Window|
|View from below|
|View from below|
Native Americans used this area for thousands of years. The Archaic peoples, and later ancestral Puebloan, Fremont, and Ute peoples, searched the arid desert for food animals, wild plant foods, and stone for tools and weapons. They also left evidence of their passing on a few pictograph and petroglyph panels. The first non-native explorers came looking for wealth in mineral forms. Ranchers found abundant grasses for cattle and sheep. Disabled Civil War veteran John Wesley Wolfe and his son Fred settled here in the late 1800s. A weathered log cabin, root cellar, and corral give evidence of the primitive ranch they operated for over 20 years.
A nagging leg injury from the Civil War prompted John Wolfe to move west from Ohio, looking for a drier climate. He chose this tract of more than 100 acres along Salt Wash for its water and grassland -- enough for a few cattle. The Wolfes built a one-room cabin, corral, and a small dam across Salt Wash. In 1906, John's daughter Flora Stanley, her husband and their children moved to the ranch. Shocked at the primitive conditions Flora convinced her father to build a new cabin with a wooden floor -- the cabin seen today. The reunited family weathered a few more years in Utah and in 1910 returned to Ohio. John Wolfe died on October 22, 1913, in Etna, Ohio, at the age of 84.
|Devils Garden Trail|
For most of Arches' long history, red rock arches did not exist. Salty inland seas, braided river systems, coastal plains, and sand dunes fill the chapters in our geologic history book. Marine fossils in the 300-million year old Honaker Trail Formation are remnants of an ancient sea. Cheerio-like discs of crinoid stems, lacy branches of bryozoans, and claim-like brachiopods tell the story of a warm, shallow sea teeming with life. Crinoids are animals that look like underwater flowers with feathery arms for collecting food. Trilobites, an early ancestor of the crab, crawled or swam among the corals. While crinoids, bryozoans, and brachiopods still exist, other animals, such as horn corals and trilobites, have been extinct for millions of years.
Fossils are not the only clues to the stories written in the rocks. Ripple marks reveal evidence of past running or lapping water. Both the main arch-forming layer, Entrada Sandstone, and the tan Navajo Sandstone, show diagonal lines called cross-bedding. These are the inner structure of ancient sand dunes frozen in time. Amazingly, geologists can figure out ancient wind direction by studying cross-bedding.