[yooper]

Alright, I'm a Civil Engineer, so I know that the dam is mucho thick concrete, though I don't know the exact thickness. I'm not sure if a jet would penetrate the dam. Any structural types out there who can provide answers?

[Ex-Dem]

It's 45 ft wide at the top, 660 wide at the bottom. 6.6 million tons of concrete (phew!).

[Las Vegas Dave]

Sad to say but a hijacked airplane would not make it to the strip, if you get my drift.....(Nellis Air Force Base is in N.Las Vegas, with interceptor jets loaded with live weapons.)