who built the large dams in the colorado river basin
Large engineering works began around the start of the 20th century, with major guidelines established in a series of international and U.S. interstate treaties known as the "Law of the River". The U.S. federal government was the main driving force behind the construction of dams and aqueducts, although many state and local water agencies were also involved. Most of the major dams were built between 1910 and 1970; the system keystone, Hoover Dam, was completed in 1935. The Colorado is now considered among the most controlled and litigated rivers in the world, with every drop of its water fully allocated.