Lake Mead National Recreation Area covers nearly a million acres of desert, canyon, and reservoir along the Nevada-Arizona border. The lake itself is the main draw — boating, kayaking, swimming, and fishing for striped bass — but the surrounding desert is also worth exploring, with slot canyons, hot springs, and surprisingly varied wildlife including bighorn sheep.
The closest access from Boulder City is the Hemenway Harbor area, with a small public beach, a marina, and boat rentals. The Alan Bible Visitor Center on the road towards the dam has trail maps, ranger talks, and an excellent introduction to the geology of the area. Entry to the recreation area requires a fee (cash or America the Beautiful pass).