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
Indigenous peoples of the North American Southwest the border of Texas and Mexico. Several Spanish explorers described this culture which was related to or derivative from the Jornada Mogollon. Between 700 and 1550 CE, the Patayan culture inhabited parts of modern-day Arizona, California and Baja California, including areas near the Colorado River Valley, nearby uplands, and north to the vicinity of the Grand Canyon. The Fremont culture inhabited sites in what is now Utah and parts of Nevada, Idaho and Colorado from 700 to 1300 CE. Archaeologists use cultural labels such as Mogollon, Ancestral Pueblo peoples, Patayan, or Hohokam to denote cultural traditions within the prehistoric American