Hoover Dam

Hoover Dam is a concrete arch-gravity dam across Black Canyon, where Nevada meets Arizona. It holds back the Colorado River to form Lake Mead, and the top is open to visitors. For the shorter visit, walk the crest; take a tour if you want to see how the structure works from inside.

You can make a quick outdoor stop or spend longer in the visitor center's self-guided exhibits and 360-degree observation deck. Guided dam and powerplant tours add interior access. The visitor center and tours are ticketed, and America the Beautiful passes don't cover them. Vehicle screening and lines can add time, so check tour availability ahead if going inside is the point of your stop.

The Dam Tour uses an original elevator and takes you into inspection tunnels near the dam's center, where a ventilation shaft opens a view toward the river. The Power Plant Tour goes through construction tunnels and stops above a 30-foot-wide penstock and the powerhouse generators. If the ticketed tours aren't your thing, the dam-top walk and canyon views still make this a memorable stop.

The dam was built to control floods, store water for irrigation and cities, and generate hydroelectric power. Construction began in 1931; workers placed the first concrete in 1933, President Franklin D. Roosevelt dedicated the dam in 1935, and its first generators came online in 1936.

The project was first known as Boulder Dam, a name carried over from the earlier Boulder Canyon site plan. Congress formally named it Hoover Dam in 1947, honoring former President Herbert Hoover.

From the observation deck, the dam, Colorado River, Lake Mead and the separate bypass bridge all fit into the view. For a photo that shows the dam's scale, keep some of the canyon wall and river in frame instead of cropping tightly around the concrete. The bypass bridge is a separate nearby stop with its own overlook.

Much of the visit is outdoors on open concrete and exposed viewing areas. In hot weather, bring water and sun protection; the high, open crossing can also feel uncomfortable if heights bother you.