I must have heard this story about a million times from different fishermen about gigantic catfish in Hoover Dam. I was told that divers used to go down there to clean up the bottom of the dam (why they were doin' that I wouldn't know) and they would see catfish equivalent to their body lengths!! Many of the divers quit after that since they didn't want to be fish-food. :-)
Has you ever else heard of these similiar stories? Are they simply urban-legends?