The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is 446 km long, up to 29 km wide and attains a depth of over a mile 1,857 meters.
The Grand Canyon was one of the first North American natural wonders to be discovered by Europeans. In 1541, a party of the Coronado expedition under Captain García López de Cardenas stood on the South Rim, 138 years before explorers found Niagara Falls, 167 before Yellowstone, and almost 300 before Yosemite. President Theodore Roosevelt was a major proponent of the preservation of the Grand Canyon area and visited it on numerous occasions to hunt and enjoy the scenery.
Even though it is not the deepest canyon in the world (Kali Gandaki Gorge in Nepal is much deeper), the Grand Canyon is known for its visually overwhelming size and its intricate and colorful landscape. Geologically, it is significant because of the thick sequence of ancient rocks that are well preserved and exposed in the walls of the canyon. These rock layers record much of the early geologic history of the North American continent.
Fascinatingly, the walls of the canyon offer an unparalleled representation of Earth’s different geologic phases. In fact, the rocks found in the walls of the Grand Canyon are believed to be approximately 1/3 of the age of the Earth itself.
The park is also home to numerous endangered plant and animal species including the desert tortoise, two species of leopard frogs, the bald eagle, American peregrine falcon, and the bighorn sheep.
The best time of year to visit the Grand Canyon is during either spring or fall, when hiking conditions are ideal, and visitor numbers slightly lower. That is not to say that you should disregard a summer trip to the canyon by any means. However, high temperatures (exceeding 100 degrees Fahrenheit) do not provide ideal hiking conditions and large crowds will be present as it’s the peak tourist season. The winter brings harsh cold (sub-zero) and the chance of heavy snowfall, which may prevent access to either rim.
According to Wikipedia