Hoover Dam was completed in the 1930's. It formed Lake Mead. It is not on an interstate and is on the only highway around with no alternate routes. Once you are on highway 93 (a nice four-lane highway), you are stuck.
What I did not know until on that highway is that, thanks to terrorists, the dam is being highly protected. Security checkpoints check out every vehicle. They are particularly watching for commercial vehicles that might be carrying explosives to blow up the dam. As such, the government is spending millions and millions of dollars on a five-year project to build a bypass around the dam. Without even directly threatening the dam, the terrorists won and the U.S. citizens lost.
Because of the security checkpoints and the thousands of vehicles, it took 45 minutes to go the 2 - 3 miles by the dam. I never did see the actual dam but did stop at a couple of pulloffs to take photos of the nearby areas.
If you want to see the dam, you need a lot of patience and a lot of time to do so. If you do see it, send me a copy of your photo so I can know what I missed. Thanks.