History of the National Park Service and multi purpose river basin development programs like the Tennessee Valley Authority which began in the 1930s and spread to river valleys in all parts of the country after World War II. Lake Mead was the first National Recreation Area. The Boulder Canyon Project Act, passed in 1928, authorized the Bureau of Reclamation to construct Hoover Dam on the Colorado River. Work began in 1931 and the dam, highest in the Western Hemisphere, was completed in 1935. The next year, under provisions of an agreement with the Bureau of Reclamation, the National Park Service assumed responsibility for all recreational activities
Steamboats of the Colorado River Colorado route, and was the model for all the steamboats on the river thereafter. From 1859, prospectors dispersed up the Colorado River valley in the next few years, finding gold deposits along the river as far as the Black Canyon. In 1860, gold was found across the Colorado River from Potholes in Arizona, in placers at La Laguna. The strikes that followed in the next four years would make George A. Johnson and his two partners wealthy. By March 1861, the secession crisis had led to the closing of the Butterfield Overland Mail. February 19, 1861, the Bascom Affair led