America's First National Recreation Area Swim, boat, hike, cycle, camp and fish at America's first and largest national recreation area. With striking landscapes and brilliant blue waters, this year-round playground spreads across 1.5 million acres of mountains, canyons, valleys and two vast lakes. See the Hoover Dam from the waters of Lake Mead or Lake Mohave, or find solitude in one of the park's nine wilderness areas.