Salmo g.: Nanophyetus salmincola is the critter. It is very abundant is much of S. Sound, including McAllister Creek, but also the Nisqually River proper. While its abundance was certainly part of the lack of survival and subsequent fishery contribution from the McAllister Creek hatchery, I suspect the real reason that WDFW finally ended that program was because of the HSRG's recommendation to close the facility. While they made recommendations on most hatchery programs,they rarely pointed to the failure of an entire facility as they did there. It was hard to argue anything else once some coded wire tags were finally placed on the fish so survival could be evaluated. Again, the assumption at that time was that all hatchery programs were or would be successful, so if you never actually evaluated them, you could always make that argument. (The WDFW version of "Don't ask, don't tell.")

As you have pointed out, there are currently a number of winter steelhead programs where the same arguments are being made.