KC, Situk is no secret spot. I've not been there during the steelhead run, but I read up alot about the area and followed the sportfishing reports cause I was going there for silvers last fall. Relative to steelhead, I remember the reports saying it is actually best in May, with a run from April through June. Fish were late last year, I think, due to La Nina.
Lodging is very tight, booked way in advance.
I couldn't get two nights consecutive in sept last year 6 months in advance, and ended up having better, more secluded fishing for silvers slightly down the coast. I dunno if the other area rivers, or for that matter, any other river in Alaska, has a run like the Situk. The Situk runs only a few miles outside of Yakutat. The river is small. I've not been there during the steelhead run, but I read up alot about the area and followed the sportfishing reports cause I was going there for silvers last fall.