As demands for Colorado River water continue to rise, the level of human development and control of the river continues to generate controversy.
For the first 250 miles (400 km) of its course, the Colorado carves its way through the mountainous Western Slope, a sparsely populated region defined by the portion of the state west of the Continental Divide.
As it flows southwest, it gains strength from many small tributaries, as well as larger ones including the Blue, Eagle and Roaring Fork rivers.
The Colorado River is one of the principal rivers of the Southwestern United States and northern Mexico (the other being the Rio Grande). After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora.
The 1,450-mile-long (2,330 km) river drains an expansive, arid watershed that encompasses parts of seven U. Known for its dramatic canyons, whitewater rapids, and eleven U. National Parks, the Colorado River system is a vital source of water for 40 million people in southwestern North America.
In Utah, the Colorado flows primarily through the "slickrock" country, which is characterized by its narrow canyons and unique "folds" created by the tilting of sedimentary rock layers along faults.
This is one of the most inaccessible regions of the continental United States.
Most of the upper river is a swift whitewater stream ranging from 200 to 500 feet (60 to 150 m) wide, the depth ranging from 6 to 30 feet (2 to 9 m), with a few notable exceptions, such as the Blackrocks reach where the river is nearly 100 feet (30 m) deep.
Arcing northwest, the Colorado begins to cut across the eponymous Colorado Plateau, a vast area of high desert centered at the Four Corners of the southwestern United States.
Beginning with small bands of nomadic hunter-gatherers, Native Americans have inhabited the Colorado River basin for at least 8,000 years.
Between 2,000 and 1,000 years ago, the river and its tributaries fostered large agricultural civilizations – some of the most sophisticated indigenous cultures in North America – which eventually faded due to a combination of severe drought and poor land use practices.
S., the river flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the international border.
The river and its tributaries are controlled by an extensive system of dams, reservoirs, and aqueducts, which in most years divert its entire flow for agricultural irrigation and domestic water supply.
Here, the climate becomes significantly drier than that in the Rocky Mountains, and the river becomes entrenched in progressively deeper gorges of bare rock, beginning with Ruby Canyon and then Westwater Canyon as it enters Utah, now once again heading southwest.