The Hoover Dam creates, or "impounds," Lake Mead. At capacity, it's the largest reservoir in the US. As you can see from all the lighter shades of ground cover, it is currently well below capacity. This overlook is on the way to the dam from Las Vegas.
For more about our tour of the dam, check out Special dam access: Tour restricted and off-limits areas of the Hoover Dam
My visit was in early January, usually a low time for Lake Mead. It will rise somewhat after the snow melts in the Rockies. However, it will still be at historically low levels due to 20 years of drought.
There are offices at the base of the dam and in the powerhouse. This is looking south, toward the Arizona side. It looks roughly the same in the other direction. Each half is basically a mirror image of the other. Note the decorations continue here too, not just on the more visible parts of the dam.
There are 17 Francis-style turbine-generators, 8 on the Nevada side, 9 on the Arizona. There are also two Pelton wheel generators, one on each side, that power the dam itself. In this photo it's the reddish-brown half-circles embedded in the floor on the lower left.
The light on top illuminates when the generator is active. As you can see, none here are generating power. As the water level in Lake Mead has dropped, the facility's ability to generate power has dropped as well.
Though tours used to visit the plant floor, that's no longer the case. You only get to see the turbines from a balcony above, and just on the Nevada side. Seeing these turbines up close radically changes their impression. These things are huge. Bigger than a two-car garage.
Seven of the turbine-generators on the Arizona side are the same size as the Nevada side's eight, two are smaller. The two smaller generators combined are roughly equal in power generation capacity to one of the larger generators.
Behind the door is a viewing area of one of the two 30-foot-wide penstocks that deliver water from the intake towers down to the turbines. This area is actually quite dark, and pretty creepy, to be honest.
A view downriver, with the bypass bridge far, far above. The structures in the upper right and upper left are the outlet works. The jet flow gates are connected to the penstocks. They can be used to bypass the turbines, but are usually only used to empty the penstocks of water for maintenance.
I had to make one last stop, and it required a bit of a walk. You can park and walk out over the Callaghan-Tillman Bridge. This is the road weaving down toward the dam, the Visitor Center off-screen to the right. Check out some of the the many power lines connecting the dam to the grid.