Hi Jack There are a number of ways to go after Steelhead and since I don't fish your water you will need to pick the best for you. as we are talking about winter fish here are a few of the options that will work. #1 floating line, long leader and weighted flys. this works well in water that is slow or shallow. Depending on depth and speed cast across or up a bit mend your line to let the fly sink before starting the swing. leader lenght 15' or more I use a 10' 7 weight or a 2 hander leader weight F-carbon 1X or heaver.
# 2 (best for winter) Sink tip,(10-15') sinking belly (20-24) or sinking head (30') my first choice is a T300 24' but depending on water depth and speed it may go down to fast. I only use it on the single hand rod. and I use unweighted flys and very short leaders 36 - 48 inch level 12lb. depending on water depth and speed cast 1/4 down to straight across and mend and let swing.
The most important thing in fly fishing of any kind is line control as for rod length longer is better for steelhead (the reason for the 2 handed rods) flys for winter fish are (for me) #2 and #4 heavy wire. and that is why I use heavy leader... takes a fair jerk to set a hook and I snag up a bunch.. I get more flys back with heavy leader.

There are a bunch of other options Too! have fun.

Rich