Rich have the fish you caught in thoes places been clipped strays or unclipped?
They are notorious for straying it's not uncommon for Skamania hatchery fish from the Washougal to be caught as far upriver as the Deschutes summer over there then return back to the Washougal.
Skamania summer runs planted in the South toutle have had a very negative impact on the wild winter steelhead there and likely have the same impact everywhere they exsist