The Grand Canyon in Arizona , USA 
Grand Canyon
            The Grand Canyon was formed by the continuous erosion of the Colorado River  valley. The mighty force of Colorado River  cut out this great gorge over thousands of years ago. Even now, year after year, the rushing waters of the Colorado River  continue to cut deeper into the bottom of the gorge. This is the deepest gorge in the world.
            The Grand  Canyon  is about 347.2 kilometers long, and extends up to 20 kilometers wide and its depth is 2 kilometers at places.
            For years, the Colorado River has slowly cut through the high plateaus of northern Arizona 
            At the bottom of the canyon, where the Colorado River  flows, is an ancient Precambrian rock that contains fossils of primitive algae. The fossils of dinosaurs, elephants, trees and other organisms of those times are found in the higher strata. The most recent rocks occur at the top of the canyon. The chain of links of the fossils provides an idea about the evolutionary process.
            Each year, more than 2 million tourists visit the grand canon to see this wonderful place. In 1919, the United States 

 
 
 
 
 
 
 
 
