Hi DS, if you are fishing the water I think you are, imo, there are very few X-large trout there. 16" - 17" is about the max that I've caught there and maybe 19" is the biggest I've ever heard of being caught there.

Now, ABOVE the lake that creates that tailwater, that's a different story.

I've caught trout up to 23" - 24" there, on small nymphs.