Fish in the Grand Ronde? Oh, there's no fish in that river...try the Yakima
If you are hell bent on driving to the vast emptyness of the GR canyon..
The water is low and should be plenty of fish by now. River is kind of cold and the fish are probably working on their overwinter coma about now, but you should be able to find some in the usual areas (in the water I mean).
The river is now really low and the water is very cold. That means the fish are lethargic and slow. If you are going to get any thing you're going to have to hit them right on the nose. Most of the fish will probably be laying in the deeper holes. there was a ton of pressure on these fish over thanksgiving weekend and there was not a lot of fish being caught then. But there should certainly be a lot of fish around, you just have to get them to bite!