Just to touch on the topic of “rules” you asked about… First, it goes without saying you need a license. Since you’re from PA I’ll assume you’ve got one. You?ll also need a Trout Stamp and a Lake Erie Stamp (or the combo stamp). You can keep three fish if you?re so inclined. Minimum size is 15" but it’s not really worth keeping anything smaller than 24". I’d also recommend some fluorocarbon leaders and tippet material 3X and 4X leaders are usually fine unless the water is very clear then you might use 5X. I’d carry some 4 lb and 6 lb tippet material for really clear conditions. You don?t have to have fluorocarbon but I think there is some benefit to using it. It helps sink your nymph, sucker spawn, egg etc. It?s virtually invisible in the water and it really helps keep break offs to a minimum.
My fly box has sucker spawn in a variety of color (white, cream, pink, egg, orange, red, yellow, chartreuse, and light blue), sizes 12 & 14, crystal meths (peach, white, orange and purple), size 12 & 14, glowbugs (eggs) (pink, light orange, bright orange, egg) sizes 10 thru 16, estaz eggs in several colors and sizes. Then there’s the nymph box with the usual stuff, stone flies, prince’s, pheasant tails, copper johns, caddis pupa and emerges, some brown drake & slate drake nymphs, hares ears, hendricksons, red tags, san juan worms, green weenie, etc. I have a box of bugger in the usual colors (black, white, olive, brown and purple) some egg sucking leeches, and an assortment of streamers.
A few weeks ago when I was up we were having really good luck on wet flies. Winged hares ears were especially productive. I don’t want to give the impression you need a lot of specialty flies 'cause you don’t. There just big trout. I think the more important thing with Steelhead is having a good, natural drift. Yes, they might get somewhat selective at times, but if you give them a proper presentation with any of the standard stuff you use for trout you can catch Steelhead.
Good luck, I’ll be up on Elk Creek Thursday, Friday and Saturday. Maybe we’ll meet on the creek!