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).

Good luck!