The GRAND Canyon
It has long been believed that the Colorado River began carving the Grand Canyon about 6 million years ago. However, a 2012 study contained shocking evidence that the process may have begun as far back as 70 million years! While still very grand, the Grand Canyon is not the deepest canyon in the world. The Yarlung Tsangpo Grand Canyon in Tibet plummets to a depth of 17,567 feet - making it a whole 2 miles deeper than the Grand Canyon's 6,093 feet! However, that first look at the canyon is one you'll never forget. Indeed, very grand and beautiful!
When visiting the Grand Canyon, sudden changes in elevation have an enormous impact on temperature and precipitation. So the weather you experience when visiting can vary drastically depending on where you are! The coldest and wettest weather station in the park is at the Bright Angel Ranger Station on the north rim. And the hottest weather station is just 8 miles away at Phantom Ranch.
Many fossils have been found that suggest creatures frequented the location up to 1.2 billions years ago. They range from ancient marine fossils to fairly recent land mammals that left their remains in canyon caves about 10,000 years ago.
Prior to modern flood control measures, the Colorado River provided a uniquely difficult habitat for fish. With heavy silt, frequent floods and temperatures ranging from extreme heat in summer to sub freezing winter temps. As a result, only 8 fish species are native to the Grand Canyon, six of which are found nowhere outside of the Colorado River. These species include: humpback chub, razorback sucker, bluehead sucker, flannelmouth sucker, speckled dace and the three extirpated species, colorado pikeminnow, roundtail chub and bonytail. 
The park offers one of the most visible examples of a worldwide geological phenomenon known as the Great Unconformity. This refers to the end result of 250 million year old rock strata lying back to back with 1.2 billion year old rocks. However, the process of how that happened or what happened to the rock between those eras is a complete mystery. 
The Grand Canyon is a sight to see and the park itself is also home to elk, fauna and over 75 species of mammals, 50 species of reptiles and over 300 species of birds.