Over 270 miles long, up to 18 miles wide and a mile deep, the Grand Canyon is known throughout the world for its overwhelming size and its intricate and colorful landscape. Located in northern Arizona, the majestic vista is geologically important because the layers of ancient rocks so beautifully preserved and exposed in the walls of the canyon reveal a timeline of Earth’s history.
In the early 1800s, trappers and expeditions sent by the U.S. government began to explore and map the Southwest, including the canyon. Although first afforded Federal protection in 1893 as a Forest Reserve and later as a National Monument, the Grand Canyon did not achieve National Park status until 1919, three years after the creation of the National Park Service. Today Grand Canyon National Park encompasses more than 1 million acres of land and receives close to 5 million visitors each year.
The Grand Canyon is part of the Colorado River basin which has developed over the past 40 million years. A recent study places the origins of the canyon beginning about 17 million years ago. Previous estimates had placed the age of the canyon at 5–6 million years. The study, which was published in the journal Science in 2008, used uranium-lead dating to analyze calcite deposits found on the walls of nine caves throughout the canyon. There is a substantial amount of controversy because this research suggests such a substantial departure from prior widely supported scientific consensus. In December 2012, a study published in the journal Science claimed new tests had suggested the Grand Canyon could be as old as 70 million years. However, this study has been criticized as “[an] attempt to push the interpretation of their new data to their limits without consideration of the whole range of other geologic data sets.
Lipan Point is a promontory located on the South Rim. This point is located to the east of the Grand Canyon Village along the Desert View Drive. There is a parking lot for visitors who care to drive along with the Canyon’s bus service that routinely stops at the point. The trailhead to the Tanner Trail is located just before the parking lot. The view from Lipan Point shows a wide array of rock strata and the Unkar Creek area in the inner canyon.
The canyon can be seen from the Toroweap (or Tuweep) Overlook situated 3000 vertical feet above the Colorado River, about 50 miles downriver from the South Rim and 70 upriver from the Grand Canyon Skywalk. This region — “one of the most remote in the United States” according to the National Park Service — is reached only by one of three lengthy dirt tracks beginning in from St. George, Utah, Colorado City or near Pipe Spring National Monument (both in Arizona). Each road traverses wild, uninhabited land for 97, 62 and 64 miles respectively. The Park Service manages the area for primitive value with minimal improvements and services.