Just got back from a 3-dayer at the Grande Ronde, and we absolutely hammered the fish!!
Took two boats down, seven guys, and we were all very successful (well some more than others

).
Day 1 - 3 steelies in our boat, 5 in the other
Day 2 - 8 steelies in our boat, 5 in the other
Day 3 - River was frozen!!
Of the 21 fish we caught, only 10 were hatchery, but that's not important. Most were caught on either plugs or corkies/yarn, but a few on spoons also.
If you dare brave the Rattlesnake Grade and long drive, it's well worth it to fish in absolute serenity without the bother of others.