The Grand canyon

The Grand Canyon of the Colorado River in northwestern Arizona is one of the earth's greatest natural wonders. It became a national park in 1919. So famous is this landmark to modern Americans that it seems surprising that it took more than thirty years for it to become a national park. President Theodore Roosevelt visited the rim in 1903 and exclaimed:

"The Grand Canyon fills me with awe. It is beyond comparison--beyond description; absolutely unparalleled throughout the wide world.... Let this great wonder of nature remain as it now is. Do nothing to mar its grandeur, sublimity and loveliness. You cannot improve on it. But what you can do is to keep it for your children, your children's children, and all who come after you, as the one great sight which every American should see."

Despite Roosevelt's enthusiasm and his strong interest in preserving land for public use, the Grand Canyon was not immediately designated as a national park. The first bill to create Grand Canyon National Park had been introduced in 1882 and again in 1883 and 1886 by Senator Benjamin Harrison. As President, Harrison established the Grand Canyon Forest Reserve in 1893. Theodore Roosevelt created the Grand Canyon Game Preserve by proclamation in 1906 and Grand Canyon National Monument in 1908. Senate bills to establish a national park were introduced and defeated in 1910 and 1911; the Grand Canyon National Park Act was finally signed by President Woodrow Wilson in 1919. The National Park Service, which had been established in 1916, assumed administration of the park.

Before the middle of the nineteenth century, very little was known about the geography of the Grand Canyon. Because of its remote location, the area in and around the canyon was not explored or mapped in detail by Europeans, although it was probably visited in 1540 by the Spanish expedition of Garcia Lopez de Cardenas, who searched with Vasques de Coronado for the seven legendary cities of Cibola. In 1776, two Spanish priests, Francisco Dominguez and Silvestre de Escalante, crossed the Colorado River while exploring the area, but little knowledge of the region was passed down in written form to later generations. The primary source of information about the magnificent canyon was an oral tradition sustained by the reports of fur trappers and traders and so-called "mountain men," most of whom were escorted through the rugged terrain by Native American guides.

Only one early visitor, Warren Augustus Ferris, is known to have produced a map showing the Grand Canyon. Drawn in 1836, it was not published until 1940, too late to be of use to the geographers and explorers who first traveled to the Colorado River and the canyon during the late nineteenth century. Ferris did, however, write and publish several articles in the 1840s, one of which described the canyon. His account added to the available information about the existence and approximate location of the Grand Canyon and served to increase interest in further exploration of the area.

The Grand Canyon is among the earth’s greatest on-going geological spectacles. Its vastness is stunning, and the evidence it reveals about the earth’s history is invaluable. The 1.5-kilometer (0.9 mile) deep gorge ranges in width from 500 m to 30 km (0.3 mile to 18.6 miles). It twists and turns 445 km (276.5 miles) and was formed during 6 million years of geologic activity and erosion by the Colorado River on the upraised earth’s crust. The buttes, spires, mesas and temples in the canyon are in fact mountains looked down upon from the rims. Horizontal strata exposed in the canyon retrace geological history over 2 billion years and represent the four major geologic eras.

Widely known for its exceptional natural beauty and considered one of the world's most visually powerful landscapes, the Grand Canyon is celebrated for its plunging depths; temple-like buttes; and vast, multihued, labyrinthine topography. Scenic wonders within park boundaries include high plateaus, plains, deserts, forests, cinder cones, lava flows, streams, waterfalls, and one of America’s great whitewater rivers.

Within park boundaries, the geologic record spans all four eras of the earth's evolutionary history, from the Precambrian to the Cenozoic. The Precambrian and Paleozoic portions of this record are particularly well exposed in canyon walls and include a rich fossil assemblage. Numerous caves shelter fossils and animal remains that extend the paleontological record into the Pleistocene.

Grand Canyon is an exceptional example of biological environments at different elevations that evolved as the river cut deeper portraying five of North America’s seven life zones within canyon walls. Flora and fauna species overlap in many of the zones and are found throughout the canyon.

The park’s diverse topography has resulted in equally diverse ecosystems. The five life zones within the canyon are represented in a remarkably small geographic area. Grand Canyon National Park is an ecological refuge, with relatively undisturbed remnants of dwindling ecosystems (such as boreal forest and desert riparian communities), and numerous endemic, rare or endangered plant and animal species.

In March 2007 one of the greatest tourist attractions at the Grand Canyon was opened - Skywalk. It is situated along the Colorado River on the edge of the canyon. Grand Canyon Skywalk is a horseshoe shaped glass walkway. With it's height of 1,200-meters (4,000 ft) above the floor of the canyon it exceeds the height of the world’s largest skyscrapers.

Natural wonder	Чудо природы
To assume administration	Взять на себя (принять) руководство чем-либо
Fur trapper	Охотник на пушных зверей
Gorge	Ущелье, каньон
Butte, spire, mesa	Возвышенность, шпиль, плоскогорье
Horizontal strata	Горизонтальный пласт, пласт горизонтального залегания
Precambrian	Докембрийский
Cenozoic	Кайнозойский
Boreal forest	Северный лес, тайга
Riparian community	Прибрежное биологическое сообщество (обитающее по берегам водоемов)

Дата добавления: 2015-07-19