SW ED-333 US-3251456 Grand Canyon

In the state of Arizona, the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted exposing nearly two billion years of Earth's geological history.  In doing so, the Colorado River carved a steep-sided canyon called the Grand Canyon. This canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,000 feet or 1,800 metres).

The Grand Canyon is part of the Grand Canyon National Park. The Park is one of the world's premier natural attractions, attracting about five million visitors per year.  Visitors to the Grand Canyon National Park generally come to the South Rim as it is open all year round.  

This second postcard of the Grand Canyon shows Mather Point.  Most visitors to the South Rim comes here as it is closest to the entrance station and is a short walk from the visitor centre.
 

Personal Note: We visited the Grand Canyon during our South-West tour.  We took a helicopter ride over the canyon during this visit.

 

The first postcard came from Bianca Swap-bot.  The second postcard came from Linda (11 March 2015) Postcrossing. 

 

SW AL-055 Monument Valley, Arizona-Utah, USA

Monument Valley is a region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, the largest reaching 1,000 ft (300 m) above the valley floor. It is located on the Arizona-Utah state line. The valley lies within the range of the Navajo Nation Reservation.

Monument Valley has been featured in many movies since the 1930s. Because of the movies,  “five square miles of Monument Valley have defined what decades of moviegoers think of when they imagine the American West."

 

The elevation of the valley floor ranges from 5,000 to 6,000 feet (1,500 to 1,800 m) above sea level. The floor is largely siltstone or sand derived from it, deposited by the meandering rivers that carved the valley. The valley's vivid red color comes from iron oxide exposed in the weathered siltstone. The darker, blue-gray rocks in the valley get their color from manganese oxide. 

The formations you see in the valley were left over after the forces of erosion worked their magic on the sandstone. A geologic uplift caused the surface to bulge and crack. Wind and water then eroded the land, and the cracks deepened and widened into gullies and canyons, which eventually became the scenery you see today. 

 

This postcard was sent by Marinda Smith (Swap-bot 24 April 2014).

We visited Monument Valley on 10 June 2008.  This is a photograph taken by me on that visit.