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 west side of the river sixty five miles above Fort Mohave near what was then considered the high water limit of navigation. George A. Johnson came up river and made a deal to supply the mines with his steamboats at $100 a ton, a lower price than the $240 a ton charged for overland freight across the Mojave Desert from Los Angeles. That fall news of the strikes brought a flood of miners to the canyon. Several camps were founded in the canyon. San Juan, or Upper Camp were at the top of the canyon, near modern Nelson, Nevada. Midway