paragraph_text: The Grand Canyon North Rim Headquarters is a historic district on the North Rim of the Grand Canyon in Grand Canyon National Park, Arizona. Established from 1926 through the 1930s, the district includes examples of National Park Service Rustic architecture as applied to employee residences, administrative facilities and service structures.

paragraph_text: At 1.6 million acres (650,000 ha) the Kaibab National Forest borders both the north and south rims of the Grand Canyon, in north-central Arizona. It is divided into three major sections: the "North Kaibab Ranger District" (offices in Fredonia) and the South Kaibab and are managed by the United States Forest Service. The South Kaibab is further divided into two districts, the "Tusayan Ranger District" (offices in the Grand Canyon), and the "Williams Ranger District" (offices in Williams). The Grand Canyon is a natural boundary between the North Kaibab and the South Kaibab. The South Kaibab covers and the North Kaibab stretches over . Elevations vary on the forest from 5,500 feet (1,676 m) in the southwest corner to 10,418 feet (3,175 m) at the summit of Kendrick Peak on the Williams Ranger District. The forest as a whole is headquartered in Williams.

paragraph_text: The Percha Diversion Dam is a structure built in 1918 on the Rio Grande in New Mexico, United States. It diverts water from the Rio Grande into the Rincon Valley Main Canal, an irrigation canal.

paragraph_text: Although Chihuahua is primarily identified with the Chihuahuan Desert for namesake, it has more forests than any other state in Mexico, with the exception of Durango. Due to its variant climate, the state has a large variety of fauna and flora. The state is mostly characterized by rugged mountainous terrain and wide river valleys. The Sierra Madre Occidental mountain range, an extension of the Rocky Mountains, dominates the state's terrain and is home to the state's greatest attraction, Las Barrancas del Cobre, or Copper Canyon, a canyon system larger and deeper than the Grand Canyon. On the slope of the Sierra Madre Occidental mountains (around the regions of Casas Grandes, Cuauhtémoc and Parral), there are vast prairies of short yellow grass, the source of the bulk of the state's agricultural production. Most of the inhabitants live along the Rio Grande Valley and the Conchos River Valley.

paragraph_text: Grand Canyon National Park, located in northwestern Arizona, is the 15th site in the United States to have been named a national park. The park's central feature is the Grand Canyon, a gorge of the Colorado River, which is often considered one of the Wonders of the World. The park, which covers 1,217,262 acres (1,901.972 sq mi; 4,926.08 km) of unincorporated area in Coconino and Mohave counties, received more than six million recreational visitors in 2017, which is the second highest count of all American national parks after Great Smoky Mountains National Park. The Grand Canyon was designated a World Heritage Site by UNESCO in 1979.

paragraph_text: Hydroelectric stations exist in at least 34 US states. The largest concentration of hydroelectric generation in the US is in the Columbia River basin, which in 2012 was the source of 44% of the nation's hydroelectricity. Hydroelectricity projects such as Hoover Dam, Grand Coulee Dam, and the Tennessee Valley Authority have become iconic large construction projects.

paragraph_text: Nearly two billion years of Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. While some aspects about the history of incision of the canyon are debated by geologists, several recent studies support the hypothesis that the Colorado River established its course through the area about 5 to 6 million years ago. Since that time, the Colorado River has driven the down - cutting of the tributaries and retreat of the cliffs, simultaneously deepening and widening the canyon.

paragraph_text: The Grand Canyon (Hopi: Ongtupqa; Yavapai: Wi: kaʼi: la, Navajo: Tsékooh Hatsoh, Spanish: Gran Cañón) is a steep - sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,093 feet or 1,857 meters).

paragraph_text: The Alpaslan-2 Dam is an embankment dam currently under construction on the Murat River in Muş Province, Turkey. The dam is located about north of the provincial capital, Muş. The primary purpose of the dam is hydroelectric power production and irrigation. Its power station will have an installed capacity of 280 MW and the reservoir will help irrigate of land. Enerjisa Power Generation Inc. acquired the license for the power station from Özışık İnsaat & Enerji in April 2011 and Yenigün Construction started excavating the diversion tunnels May 2012. The diversion tunnels are expected to be complete by the end of 2012. In late May 2013 Pöyry was awarded the detailed design of the dam, power station, spillway and switch yard. Enerjisa expects the project to be complete in 2016.

paragraph_text: The Grand Valley Diversion Dam is a diversion dam in the De Beque Canyon of the Colorado River, about northeast of Grand Junction, Colorado in the United States. It is a high, long concrete roller dam with six gates, which were the first and largest of their kind to be installed in the United States.

paragraph_text: U.S. President Theodore Roosevelt visited the Grand Canyon in 1903. An avid outdoorsman and staunch conservationist, Roosevelt established the Grand Canyon Game Preserve on November 28, 1906. Livestock grazing was reduced, but predators such as mountain lions, eagles, and wolves were eradicated. Roosevelt along with other members of his conservation group, the Boone and Crockett Club helped form the National Parks Association, which in turn lobbied for the Antiquities Act of 1906 which gave Roosevelt the power to create national monuments. Once the act was passed, Roosevelt immediately added adjacent national forest lands and redesignated the preserve a U.S. National Monument on January 11, 1908. Opponents such as land and mining claim holders blocked efforts to reclassify the monument as a U.S. National Park for 11 years. Grand Canyon National Park was finally established as the 17th U.S. National Park by an Act of Congress signed into law by President Woodrow Wilson on February 26, 1919.

paragraph_text: The Grand Canyon is a river valley in the Colorado Plateau that exposes uplifted Proterozoic and Paleozoic strata, and is also one of the six distinct physiographic sections of the Colorado Plateau province. It is not the deepest canyon in the world (Kali Gandaki Gorge in Nepal is much deeper). However, the Grand Canyon is known for its visually overwhelming size and its intricate and colorful landscape. Geologically, it is significant because of the thick sequence of ancient rocks that are well preserved and exposed in the walls of the canyon. These rock layers record much of the early geologic history of the North American continent.

paragraph_text: Byers Canyon is a short gorge on the upper Colorado River in Grand County, Colorado in the United States. The canyon is approximately 8 miles (13 km) long and is located in the headwaters region of the Colorado between Hot Sulphur Springs and Kremmling. U.S. Highway 40 passes through the canyon between Hot Sulphur Springs and Kremmling. The Union Pacific Railroad's Moffat Route also travels through the short canyon.

paragraph_text: Canyon Creek is a hamlet in northern Alberta, Canada within the Municipal District of Lesser Slave River No. 124. It is located on Highway 2, approximately east of Grande Prairie.

paragraph_text: This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Grand Canyon National Park, Arizona, United States. The locations of National Register properties and districts for which the latitude and longitude coordinates are included below, may be seen in a Google map.

paragraph_text: The Marimbondo Dam is an embankment dam on the Grande River near Fronteira in Minas Gerais, Brazil. The dam serves an associated hydroelectric power plant with a installed capacity.

paragraph_text: SS "Grand Canyon State" (T-ACS-3) is a crane ship in ready reserve for the United States Navy. The ship was named for the state of Arizona, which is also known as the "Grand Canyon State".

paragraph_text: Cimarron Hydroelectric Power Project a hydroelectric power plant in El Salvador, that was to start construction in 2010. The plant would have been be located in the upper basin of the Lempa River, upstream of the Cerrón Grande Hydroelectric Dam. The proposed location of the dam was between the towns of Agua Caliente, Chalatenango on the left shore and Metapán, Santa Ana, on the right shore. A tunnel would divert water from the Lempa River to a powerhouse and substation to be built near Agua Caliente. With an estimated capacity of 261 megawatts, the project would have increased El Salvador's total generation capacity by almost 25%.

paragraph_text: Hopi House is located on the South Rim of the Grand Canyon, within Grand Canyon National Park in the U.S. state of Arizona. Built in 1904 as concessioner facilities at the South Rim were being developed, it is the first of eight projects at the Grand Canyon that were designed by architect Mary Colter, along with Bright Angel Lodge, Hermit's Rest, Lookout Studio, Phantom Ranch, Desert View Watchtower, Colter Hall and Victor Hall, (the latter two being employee dormitories). Hopi House was built by the Fred Harvey Company as a market for Native American crafts, made by artisans on the site. The Hopi, as the historic inhabitants of the area, were chosen as the featured artisans, and the building was designed to closely resemble a traditional Hopi pueblo. Hopi House opened on January 1, 1905, two weeks before the El Tovar Hotel, located just to the west, was opened.

paragraph_text: The Town of Cedaredge is a Home Rule Municipality in Delta County, Colorado, United States. The town population was 2253 at the 2010 United States Census. Cedaredge sits in the Surface Creek Valley beneath the southern slopes of the Grand Mesa, the largest mesa in the world. Its elevated vantage point affords southern views of the San Juan Mountains, the Black Canyon of the Gunnison National Park, and the communities of Delta, Olathe, and Montrose. Cedaredge is a small, agricultural community which produces beef cattle, apples, peaches, and wine from the region's few basic vineyards. Tourist attractions include Cedaredge Golf Club, Historic Pioneer Town, and an art gallery and craft store housed in a renovated apple packing shed. Regional sporting activities include camping, trophy hunting, hiking and Gold Medal fishing at more than 250 lakes on the Grand Mesa. During the winter locals partake in snowmobiling and Nordic skiing on the Mesa's trails. Powderhorn Resort is located north of Cedaredge and has ski terrain such as groomers, bumps, glades, and boulder fields, as well as two terrain parks.

Question: When did the river on which the Grand Valley Diversion Dam is located start forming the Grand Canyon?
Answer: about 5 to 6 million years ago