North Rim of the Grand Canyon
36.217283°N 112.056581°W

July, 1985

North Rim of the Grand Canyon
36.204256°N 112.053178°W

July, 1985

North Rim of the Grand Canyon
36.204358°N 112.053511°W

July, 1985

North Rim of the Grand Canyon
36.199894°N 112.052322°W

July, 1985

Grand Canyon Stratigraphy

The stratigraphic record exposed by the erosion of the Grand Canyon by the Colorado River.

Major John Wesley Powel’s boats

Photograph taken about 1872 of Major John Wesley Powel’s boats on the Colorado River. No photographs exist from his first expedition – the photograph is of his second expedition.

Theodore Roosevelt visited the Grand Canyon in 1903 and pushed to have it protected. He signed the legislation making it a national park on November 28, 1906. It is now considered one of the seven natural wonders of the world.

The Grand Canyon is being carved by the Colorado River as the Colorado Plateau is being slowly pushed upward by forces deep within the earth. The age of the Grand Canyon has been dated by calcite deposits along the strata to be about 17 million years old. The erosion has exposed more than a mile of mostly horizontal strata dating back to 1.8 billion years ago. In fact, the Canyon has exposed rocks from the PreCambrian (The Vishnu Schist - 1.9 billion years old) to the Permian (Kaibab Formation - 270 million-years old).

The Ancient Pueblo People were the first humans to reside in the Grand Canyon area. In September, 1540, Captain Garcia Lopez de Cardena was sent north by Francisco Vázquez de Coronado during his western exploration, to do reconnaissance. Cardena along with Hopi guides reached the south rim of the canyon where three of the soldiers made it about a third of the way off the rim. In 1869 former Civil War veteran, Major John Wesley Powell, led the first expedition down the Colorado River with nine other men and 4 boats. Powell lost an arm during the war but managed to make the treacherous journey along with six others. Three of his men decided to leave the party during the trip and climbed out of the canyon where they were killed by hostile Native Americans.

Jack Crane

View of the North Rim of the Grand Canyon

Grand Canyon National Park is the United States' 15th oldest national park. Named a UNESCO World Heritage Site in 1979, the park is located in Arizona. The park's central feature is the Grand Canyon, a gorge of the Colorado River, which is often considered one of the Seven Natural Wonders of the World. The park covers 1,217,262 acres (1,902 sq mi; 4,926 km) of unincorporated area in Coconino and Mohave counties.

• http://en.wikipedia.org/wiki/Grand Canyon National Park
• Hillman 1000 Wonders