Posted on April 28 2021
By Becky Sicking
The Grand Canyon became a national park on February 26, 1919. President Woodrow Wilson signed a bill that established the park under the National Park Service (NPS). The canyon was not the first park to receive this honor. As early as 1872, Congress made Yellowstone the nation’s first national park. At that time, however, the National Park Service (NPS) did not exist yet. The NPS was created when Wilson signed a different bill, in 1917.
Land conservation developed out of the Progressive Era in American history, from 1890-1920. Progressivism was a social movement that focused on matters of public interest, such as child labor and access to public education. As a result of interest in the common good, the movement looked at conserving nature from development. It comes as no surprise then that the Grand Canyon was swept up into this movement. It is one of America’s most amazing natural wonders.
According to the most recent data from the NPS, over 4.5 million people visit Grand Canyon National Park, located in Arizona, each year. The park is divided into the South Rim, which is far easier to access, and the North Rim, which is closed to visitors during winter. Visitors can enjoy the 358 miles of trails established in the park. Not all of these are maintained, however, so if visiting be sure to plan accordingly. There are visitor centers that include museums and a theater, and the park even has lodging available for overnight stays. The scenic overlooks allow guests to see the canyon in all its glory. The sunlight reveals the numerous colors of the canyon, which are the result of different sedimentary rock deposits over time. Sunset is especially beautiful over the canyon.
The canyon evolved from the Colorado River carving down through the rock layers beneath its path, beginning about six million years ago, when it followed its current course. The river runs rapidly and brought large amounts of mud, sand, and gravel as it flowed. These deposits helped account for the river’s amazing capacity to cut out the canyon. Today, erosion and active tectonic shifts continue to shape the canyon.
The exposure of the rocks along the canyon walls provides an incredible record of Earth’s geologic history. The inner gorge incudes granite and schist that is more than 2.5 billion years old. Over these ancient rocks are layers of limestone, sandstone, and shales that are more than 540 million years old. Overlying these deposits further are still more strata of rock from approximately 300 million years ago. Rocks from the Mesozoic Era, from 250 million to 65 million years ago, do not exist at the canyon, however. They have been entirely eroded away. Relatively recent rock formations include sheets of black lava from volcanic cones that were active perhaps within the last 1,000 years. Combined, the rocks provide a geologic record of Earth in that area.
In addition to the geology of the area, scientists recognize the diverse animal and plant life at the Grand Canyon. Nearly 400 species of birds and 92 species of mammals, including bighorn sheep, mountain lions, mule deer, and ringtail cats, live at the Grand Canyon. With its various elevations, from the low of the canyon floor to the highs of the canyon rim above, there are six main plant communities. These range from riparian at the canyon floor, to desert scrub to pinyon woodlands to pine forests and then to subalpine mountain meadows at the North Rim. In all, there are about 1,800 known plant species in the park.
The climate of the Grand Canyon is relatively mild, with temperatures ranging from an average of 63 to 35 degrees Fahrenheit at the South Rim. The North Rim averages are cooler, with a range of between 56 and 30 degrees Fahrenheit. There is also relatively low precipitation with a yearly average of 15.6 inches at the South Rim compared to 25.3 inches on the North Rim.
According to the oldest artifacts found at the Grand Canyon, humans first lived there about 12,000 years ago. Archaeologists have discovered evidence from numerous culture groups since that time. Ancestral Puebloan people, Hopi, Navajo, Zuni, and Euro-Americans have all lived in the area. Only six percent of the park has been surveyed to find human artifacts. Native American tribes consider the management of archaeological evidence of human life at the Grand Canyon as preservation of their cultural heritage. Today, there is a large Navajo Nation reservation just east of the park, while the smaller Hualapai reservation is west of the park.
Thanks to President Wilson’s establishment of the Grand Canyon as a national park on February 26, 1919, visitors from all over the world can come and explore this natural wonder, learn about the people who lived there, discover the beauty of the landscape, and see for themselves the power of water and time.