Which National Park Service site became the first national recreation area established by Congress?

Lake Mead National Recreation Area became the first national recreation area established by Congress.

The landscape around the future reservoir was first managed as Boulder Dam Recreation Area in 1936, after the National Park Service agreed to provide recreation services around Hoover Dam. Congress formally designated Lake Mead National Recreation Area in 1964, making it the first national recreation area created by statute.

The area follows the Colorado River through southeastern Nevada and northwestern Arizona. It includes Lake Mead, Lake Mohave, desert mountains, canyons, and large stretches of shoreline. Hoover Dam created Lake Mead, while Davis Dam created Lake Mohave.

This designation broadened the National Park Service mission beyond traditional national parks and monuments. National recreation areas generally combine outdoor recreation with other major purposes, such as water storage, urban access, or reservoir management. The name was changed from Boulder Dam Recreation Area to Lake Mead National Recreation Area in 1947.