Youv'e got a task in front of you, catching a winter steelhead on a flyrod isnt easy.

I fish in the Sauk, Skagit, Nooksack, and Stilly during the winter. The waters normaly really cold causing the fish to be lethargic.
The water is often fast and deep. So going low and slow is normally the only way to get the fish.

I fish with a sink-tip line, using the ultra fast sink tip that came with my Airflo multi-tip line. Its nice because it sinks your fly while the floating line allows you to mend giving you control of drag during the presentation. I normaly use a 3 to 4 foot leader attached to my sinktip because it keeps the fly down and being that the water normaly has color to it doesnt bother the fish.

Some people like to use shooting heads, but Ive never tried it. And couple of my budys prefer to fish a floating line with a long leader and weight.

The most common presentation is casting across the stream, mending the belly out of the 3 or 4 times and then letting the fly swing beneath you, and then stripping it in.

Good luck, and fun fishing,
Josh