I've caught some 2-3lb whitefish on the middle fork snoqualmie while trout fishing (sorry - but no bait up there).

On the lower river (where the raging come in), I stopped and watched an old timer catching them left and right. He had a long noodle rod (at least 10 ft) and an ultra light reel with 4lb line. He was using a dropper weight with 2 short leaders (about 12 inches or less) staggered up the line at 90 degree angles. His bait was some kind of small whitefish nymph flies tipped with white grubs/maggots. He just flipped it a little ways into the current and let it drift about 10 to 20 feet - keeping constant pressure on the line to feel subtle takes. He said he often hooks up with steelhead doing this as well...

Also, the yakima kicks out some good sized whitefish.

Just remember that, while they can be fished for just like trout, they have smaller mouths than trout. They will hit flys in the surface too. But that small mouth can equal frustration if they can't get the hook in their mouth...

Well, that's about all I know about them too... I must admit though, when I'm out steelheading in the winter, and don't see a fish for hours - i sometimes stick on some smaller lure/bait and try to hook a few of these guys just to remind me what a fish feels like (although they don't fight as well as a trout, they can still be fun).

-Chad