Question: What is the source of the river that carved the mile deep channel that is the Grand Canyon?

full_context: Document 1: Gore Canyon: Gore Canyon is a short isolated canyon on the upper Colorado River in southwestern Grand County, Colorado in the United States. The steep and rugged canyon, approximately 3 miles (5 km) long, was carved by the river as it passed the northern end of the Gore Range southwest of Kremmling. The Colorado descends from approximately to approximately over the length of the canyon. The steep walls ascend approximately on either side. The canyon effectively marks the southwestern end of the Middle Park basin in north central Colorado.
Document 2: Grand Canyon: 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.
Document 3: Colorado River Compact: The Colorado River Compact is a 1922 agreement among seven U.S. states in the basin of the Colorado River in the American Southwest governing the allocation of the water rights to the river's water among the parties of the interstate compact. The agreement was signed at a meeting at Bishop's Lodge, near Santa Fe, New Mexico, by representatives of the seven states the Colorado river and its tributaries pass through on the way to Mexico.
Document 4: Grand Canyon: 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).
Document 5: Range Creek: Range Creek, rising in the Book Cliffs in Emery County, Utah, is a high tributary of the Colorado River. It flows into the Green River, a major tributary of the Colorado. The creek flows year around.
Document 6: Roaring Rapids (Colorado River): Roaring Rapids are one of several rapids in the Black Canyon of the Colorado, 10.25 miles above El Dorado Canyon in the Colorado River between Arizona and Nevada.
Document 7: Grand Canyon National Park: 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.
Document 8: Colorado River: Colorado River The Colorado River at Horseshoe Bend, Arizona, a few miles below Glen Canyon Dam Countries United States, Mexico States Colorado, Utah, Arizona, Nevada, California, Baja California, Sonora Tributaries - left Fraser River, Blue River, Eagle River, Roaring Fork River, Gunnison River, Dolores River, San Juan River, Little Colorado River, Bill Williams River, Gila River - right Green River, Dirty Devil River, Escalante River, Kanab River, Virgin River, Hardy River Cities Glenwood Springs, CO, Grand Junction, CO, Moab, UT, Page, AZ, Bullhead City, AZ, Lake Havasu City, AZ, Yuma, AZ, San Luis Rio Colorado, SON Source La Poudre Pass - location Rocky Mountains, Colorado, United States - elevation 10,184 ft (3,104 m) - coordinates 40 ° 28 ′ 20 ''N 105 ° 49 ′ 34'' W ﻿ / ﻿ 40.47222 ° N 105.82611 ° W ﻿ / 40.47222; - 105.82611 Mouth Gulf of California - location Colorado River Delta, Baja California -- Sonora, Mexico - elevation 0 ft (0 m) - coordinates 31 ° 54 ′ 00 ''N 114 ° 57 ′ 03'' W ﻿ / ﻿ 31.90000 ° N 114.95083 ° W ﻿ / 31.90000; - 114.95083 Coordinates: 31 ° 54 ′ 00 ''N 114 ° 57 ′ 03'' W ﻿ / ﻿ 31.90000 ° N 114.95083 ° W ﻿ / 31.90000; - 114.95083 Length 1,450 mi (2,334 km) Basin 246,000 sq mi (637,137 km) Discharge for mouth (average virgin flow), max and min at Topock, AZ, 300 mi (480 km) from the mouth - average 22,500 cu ft / s (637 m / s) - max 384,000 cu ft / s (10,900 m / s) - min 422 cu ft / s (12 m / s) Map of the Colorado River basin Wikimedia Commons: Colorado River
Document 9: Hells Canyon: Hells Canyon is a 10 - mile (16 km) wide canyon located along the border of eastern Oregon, eastern Washington and western Idaho in the United States. It is part of the Hells Canyon National Recreation Area and is North America's deepest river gorge at 7,993 feet (2,436 m).
Document 10: Mars: The large canyon, Valles Marineris (Latin for ``Mariner Valleys '', also known as Agathadaemon in the old canal maps), has a length of 4,000 km (2,500 mi) and a depth of up to 7 km (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one - fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 km (277 mi) long and nearly 2 km (1.2 mi) deep. Valles Marineris was formed due to the swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where 150 km (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two - tectonic plate arrangement.
Document 11: Dolores River: The Dolores River is a tributary of the Colorado River, approximately long, in the U.S. states of Colorado and Utah. The river drains a rugged and arid region of the Colorado Plateau west of the San Juan Mountains. Its name derives from the Spanish "El Rio de Nuestra Señora de Dolores", River of Our Lady of Sorrows. The river was explored and possibly named by Juan Maria Antonio Rivera during a 1765 expedition from Santa Fe.
Document 12: Water in California: The Colorado River originates more than 1,000 miles (1,600 km) from California in the Rocky Mountains of Colorado and Wyoming and forms the state's southeastern border in the Mojave Desert. Unlike the other California watersheds, essentially all of the water flowing in the Colorado originates outside the state. The Colorado is a critical source of irrigation and urban water for southern California, providing between 55 and 65 percent of the total supply.
Document 13: Grand Canyon: 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.
Document 14: Colorado River (Texas): Colorado River Texas The Colorado River in Austin, as seen from Mount Bonnell. Country United States State Texas Source - location Dawson County - elevation 3,280 ft (1,000 m) - coordinates 32 ° 40 ′ 47 ''N 101 ° 43 ′ 51'' W ﻿ / ﻿ 32.67972 ° N 101.73083 ° W ﻿ / 32.67972; - 101.73083 Mouth Matagorda Bay - location Gulf of Mexico, at Matagorda County, Texas - elevation 0 ft (0 m) - coordinates 28 ° 35 ′ 41 ''N 95 ° 58 ′ 59'' W ﻿ / ﻿ 28.59472 ° N 95.98306 ° W ﻿ / 28.59472; - 95.98306 Coordinates: 28 ° 35 ′ 41 ''N 95 ° 58 ′ 59'' W ﻿ / ﻿ 28.59472 ° N 95.98306 ° W ﻿ / 28.59472; - 95.98306 Length 862 mi (1,387 km) Basin 39,900 sq mi (103,341 km) Discharge for Bay City - average 2,609 cu ft / s (74 m / s) - max 84,100 cu ft / s (2,381 m / s) - min 0 cu ft / s (0 m / s) Map of the Colorado River and associated watershed
Document 15: Grand Canyon National Park: Grand Canyon National Park IUCN category II (national park) Grand Canyon from the South Rim at dawn Location Coconino and Mohave counties, Arizona, United States Nearest city Fredonia, Arizona (North Rim) Tusayan, Arizona (South Rim) Coordinates 36 ° 03 ′ 19 ''N 112 ° 07 ′ 19'' W ﻿ / ﻿ 36.0552608 ° N 112.1218355 ° W ﻿ / 36.0552608; - 112.1218355 Coordinates: 36 ° 03 ′ 19 ''N 112 ° 07 ′ 19'' W ﻿ / ﻿ 36.0552608 ° N 112.1218355 ° W ﻿ / 36.0552608; - 112.1218355 Area 1,217,262 acres (4,926.08 km) Established February 26, 1919 (1919 - 02 - 26) Visitors 6,254,238 (in 2017) Governing body National Park Service Website Grand Canyon National Park ``The template Infobox UNESCO World Heritage Site is being considered for merging. ''UNESCO World Heritage Site Criteria Natural: vii, viii, ix, x Reference 75 Inscription 1979 (3rd Session)
ground_truth: La Poudre Pass
sub_queries: what river carved the mile deep channel that is the grand canyon Answer: Colorado River
what is the source of Colorado River Answer: La Poudre Pass