Colorado River too much of the lower basin allotment; in 1944 a compromise was reached in which Arizona would get a firm allocation of , but only if California's allocation was prioritized during drought years. These and nine other decisions, compacts, federal acts and agreements made between 1922 and 1973 form what is now known as the Law of the River. On September 30, 1935, the United States Bureau of Reclamation (USBR) completed Hoover Dam in the Black Canyon of the Colorado River. Behind the dam rose Lake Mead, the largest artificial lake in the U.S., capable of holding more than two
Agriculture in the Southwestern United States Agriculture in the Southwestern United States Agriculture in the Southwest United States is very important economically in that region. The three main watersheds of the southwest United States are the Colorado River Basin, the Great Basin, and the Rio Grande Basin. The Colorado River Basin includes parts of California, Utah, Arizona, New Mexico, Colorado, and Wyoming. The Colorado River is the largest river in the Southwest United States. The Great Basin watershed includes parts of southern California, most of Utah, the northwest half of Nevada, and parts of Oregon and Idaho. The Rio Grande Basin includes most of New Mexico,