Drifter -
The move from the Saturday before memorial Day to June first was concern about both potential angler impacts on both smolt and spawning steelhead. While there always is a desire for consistent regulations specific angler desires and concerns often lead to more complex regulations.

As with this year Memorial Day can fall as early as 25th of May meaning that "opening day" could be as early as May 23. Peak out migration of steelhead smolts is typically during the second week of May (sometimes a bit later) and usually tapers off into early June. Wild steelhead spawning can extend well into June and on basins like the Skagit/Sauk/Nooksack the peak spawning activity of wild winter steelhead occurs in mid-May. Bottom line significant numbers of both wild smolts and spawning wild winters are still in the rivers in late May and by moving to June first opening their exposure is reduced by 3 to 9 days; while that may not seem a like a lot some years and in some basins it is significant.

There was a back lash from the June first opener by those that liked the traditional Saturday opening. On the other side of the coin many of those that fish salmon (spring and summer Chinook) in rivers wanted as many days possible to access the fish.

There was also a backlash against the move from the Saturday before Memorial Day by those that want to that a three day weekend or that benefit from that recreational activity that such weekends generate. The end result we have ended up with many of the rivers with just resident trout (especially in eastern Washington) opening on the Saturday before Memorial Day. While the general opener for streams with anadromous fish being the first Saturday in June with an exception for those will or the potential for early salmon season.

Complicated -yes; confusing for sure but the above is my recollection of the rationale for the various opening day changes over the last 30 years.

Hope that helps.

Curt