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 Quartette Landing and Eldorado Canyon in Nevada, the landings and the mills there were abandoned. The town of Nelson was founded near the head of the canyon nearest the road to the railroad, the post office of Eldorado was closed in August 31, 1907 and moved to Nelson. In 1906, Santa Fé railroad built the Barnwell and Searchlight Railway to the west to tie Searchlight to its subsidiary California Eastern Railway at Barnwell, California. Also in 1905, the Arizona and California Railroad bridged the Colorado River at Parker, Arizona, cutting in half the last profitable section of the river for