The forces that have shaped the area around Lake Mead include collisions between continents, extension that stretched and fractured the Earth’s crust, volcanic eruptions, inundation by tropical seas, growth and decline of great deserts and lakes, and finally, sculpting of the land by water and wind. Evidence of these processes is dramatically displayed in Lake Mead National Recreation Area.
Grand Classroom participants take the "Discovery Tour" at Hoover dam that allows them to hear a lectured presentation by professional guides, access to the Exhibit Hall, Visitor's Center, the indoor/outdoor observations decks and a 25 minute movie on the dam's original construction.
Viewing this magnificent, massive man made structure creates a respect for man's accomplishments. The strong desire to harness nature's power drove the human mind and body to build Hoover Dam in the hottest, driest area of the United States. In doing so, the seasonal flooding of the Colorado River was eliminated and millions of people now have drinking water and irrigation during the dry season. Students learn how the builders triumphed over environmental and engineering difficulties to complete the monumental task to build the largest dam known to man in 1935.
Native Americans were the first to enjoy the canyon, inhabiting the areas surrounding it. The Anasazi, ancestral to the Pueblo, established themselves at Grand Canyon by A.D. 500. They lived in semi-subterranean dwellings. By around A.D. 1000, they had developed a communal culture that can best be seen through the ruins at Tusayan Pueblo. Eventually, drought forced the Pueblo to move and after another century and a half, another native group, the Cerbat, moved into the area and their descendants, the Hualapai and the Havasupai tribes still inhabit the region today. The most recent indigenous group to occupy the Grand Canyon area is the Navajo who settled in the area around the beginning of the 15th century. Their resourcefulness and willingness to adapt allowed them to endure years of conflicts with European settlers and other native tribes. Today they occupy a reservation adjacent to Grand Canyon.
Canyon was formed over millions of years as tectonic movement forced the Colorado River to forge a new route before it emptied into present day Gulf of California. Erosion, weathering, and climate played a major role in carving the canyon we see today. These processes allow us to see the rock layers, or strata, that provide a window into the past. Most of the layers are comprised of sedimentary rock as the Colorado and its tributaries deposited some of its contents on its way to the sea. Over time, these contents hardened and have become the soft shale and limestone of today.
Since Grand Canyon spans over 8,000 ft. in elevation, it harbors wildlife whose habitat range from arid desert to mountainous environments. Three main regions characterize the environments local to Grand Canyon: 1. The Rim or Coniferous Forest Region, 2. The Inner Canyon or Desert Scrub Region, and 3. The Colorado River and Inner Gorge, or Riparian Region. Within each region lies a distinct group of plant and animal life.
Wupatki was the grandest of the pueblos in the Grand Canyon region. Pueblo, from the Spanish “town” referred to the masonry of the apartment-like dwellings where the people lived. Most scholars believe that the eruption of Sunset Crater Volcano led to its creation. In the years following the eruption, the ash provided a base layer on the ground that held moisture, making the land more arable. As the agriculture made the area more viable, spread out populations became more centralized, moving into the pueblos. It is believed the inhabitants of Wupatki only inhabited the area briefly before moving on.