Few places in the world are so simply -- and aptly -- named. How much do you know about America's Grand Canyon?
In 1893, parts of the canyon were named a Forest Reserve, which helped to restrict certain human activities. Now, the area is a national park and subject to tight regulations.
Current estimates guess the canyon's age at around 17 million years old. The ground was eroded by flowing water, exposing layer after layer of ancient rock.
The deepest point of the Grand Canyon is about 7,800 feet, or well over 1 mile. But the Yarlung Tsangpo Grand Canyon in the Himalayas is much deeper, at more than 17,000 feet deep in some areas.
Woodrow Wilson gets credit for creating the national park. However, Benjamin Harrison was a long-time proponent of the canyon, and he introduced park legislation long before the turn of the century.
The South Rim is one of the most accessible areas of the canyon, and it's where most tourists spend their time. The North Rim is more remote and requires more arduous travel.
The Colorado River courses through the bottom of the canyon, wearing away the rock to ever deeper dimensions. The river begins in Colorado and ends Baja California.
The Grand Canyon is beautiful, but it can be hazardous to human health -- more than 700 people have perished there since the 1870s. People die due to the weather, falls, drownings and a plethora of other dangers.
The Tonto Group is near the bottom of the canyon, and thus, one of the oldest layers of rock exposed in the canyon. This group is about 1,200 feet thick.
The narrowest point of the canyon is about 600 yards. At its widest, it is 18 miles across. The average width is about 10 miles.
The South Rim is often jam-packed with tourists and cars, but it still draws the vast majority of visitors. By some estimates, about 90% of visitors see only the South Rim area.
Few people live in the vicinity of the canyon, meaning that the air here is some of the cleanest in the country. On a clear day, you can see for nearly 100 miles.
The World Heritage Site designation means that the United Nations recognizes the canyon as an area of cultural importance. The park was declared a Heritage site in 1979.
The Canyon is around 270 miles long. It stretches throughout the northwest corner of Arizona.
John S. Newberry was the first geologist to study the canyon. In 1858, he began creating cross-section illustrations of the canyon rock in order to better understand its formations.
It takes the better part of the day for hikers to simply make the one-way trip to the bottom of the canyon. For safety reasons, park officials strongly advise against people trying to descend to the river and then climb up again in the same day.
The trip from the heavily visited South Rim to the more remote North Rim is a journey of about 250 miles by car. It takes roughly five hours to make the drive.
Soft limestone crowns many areas of the tops of the canyon. It is the first layer to be carried away when erosion begins in earnest.
At the time, the crash was the deadliest in the history of flight -- 128 people perished as the planes plunged into the eastern part of the canyon. The accident led to the creation of the Federal Aviation Administration.
About 70 different types of mammals live around the canyon. There are also five species of amphibians and 25 types of reptiles.
The canyon did have federal protection starting in the early 1890s, but it wasn't established as a national park until 1919. The park encompasses about 1.2 million acres.
Teddy Roosevelt, always awed by nature's grandeur, was particularly overwhelmed by the canyon. He implored Americans to pass legislation protecting the canyon for future generations.
The North Rim's roads are often impassable due to snow, so it is closed to tourists in late fall to early spring. The South Rim, however, is open throughout the year.
Grand Canyon National Park is about 1,900 square miles. It's so large that even from the higher North Rim, visitors can see only a fraction of the canyon's expanse.
This national park is one of the most popular tourist destinations in the world. About 5 million people make the journey to the canyon each year.
Point Imperial is the highest area of the canyon. It rests at 8,800 feet above sea level, on the canyon's North Rim.
It seems hard to believe, but it's true -- it took more than 230 years for Europeans to finally set foot on the North Rim of the canyon. The North Rim's rugged remoteness is vastly different than the busy South Rim.
Powell's adventure lasted about three months. His treacherous journey came at the expense of several lives, but his records helped to develop the first maps of the area.
Scientists have found remnants of civilizations dating back to nearly 12,000 years ago. It wasn't until the 1800s, though, that European descendants began to map the area in earnest.
The North Rim sits at an elevation of about 8,200 feet. In contrast, the highest point of the South Rim is 7,400 feet.
More than four decades ago, in 1975, Marble Canyon National Monument was ended … because it was then reintroduced as part of the larger national park system.