On February 26, 1919, the Grand Canyon was designated as a National Park. Often described as one of the seven natural wonders of the world, the Grand Canyon was given its name by John Wesley Powell who led an expedition through the area in 1869. The national park includes 1,218,375 acres of land on the Colorado Plateau. The Grand Canyon is an amazing example of erosion. Its widest span is 18 miles in length, and its deepest point is approximately 6,000 feet below the plateau. It stretches for 277 miles. There are three major groups of strata in the canyon. The rocks on the floor of the canyon are from the Proterozoic Period and estimated to be 1.84 billion years old. They are sometimes referred to as basement rocks. Lying above basement rocks are Late Precambrian rocks which are 740 to 1,200 million years of age. Finally, the spectacularly layered rocks visible from the rim of the Grand Canyon were formed in the Paleozoic period and thought to be 270 to 525 million years of age. The canyon is a geologic gold mine. Marine and terrestrial sediment deposits can be seen in almost 40 sedimentary layers. Lava dams were deposited by volcanos in the area almost 2 million years ago. Plate tectonic movement created metamorphic rocks now referred to as the Granite Gorge Metamorphic Suite. Amazingly, the erosional pattern created by the Colorado River is a relatively recent development in the canyon. It began sometime between 3 and 6 million years ago.
Did you know that it took almost 40 years to have the Grand Canyon included in the National Park System? Benjamin Harrison (who at that time was a Senator from Indiana) introduced bills in 1882, 1883, and 1886 to create the Grand Canyon National Park. All three attempts were unsuccessful. After Harrison became president, he created the Grand Canyon Forest Reserve. The reserve encompassed more than 17 million acres. The Antiquities Act, passed in 1906, allowed the President to establish national monuments without the consent of the Congress. Theodore Roosevelt used this act to first proclaim the canyon to also be a game preserve in 1906, and later named it as a National Monument. Opposition grew overtime against including the Grand Canyon in the list national park system because of interest in the developing the area for both tourism and agriculture. Bills that were introduced in both 1910 and 1911 did not even make it to a vote on the floor of the Congress. In 1917, a sixth bill was introduced, but Congress adjourned without voting on it. In 1918, Interior Secretary Franklin Lane sent a letter to Senator Myers, who chaired the Public Lands Committee, and strongly voiced his opinion that a national park be created to preserve the Grand Canyon’s natural beauty. On May 16, 1918, the Senate acted. A revised version of the Senate bill was passed by both houses of the Sixty-fifth Congress. It was signed into law by Woodrow Wilson on February 26, 1919.
The Grand Canyon National Park has an estimated five million visitors each year. You can visit the portion of the National Park System’s website by visiting: http://www.nps.gov/grca/index.htm