Just go to Sweet home. Turn left at the Foster dam. Go over dam.
Turn left. Follow road little ways down till you see the hatchery. Park. Go to dead line. Or... Pass by hatchery till you see the church sign then park in turn out in the the gravel parking lot. Follow signs that say "fisherman this way."
I use flies and lures even though it's open for bait. I hate that they opened it for bait. There is a lot of REALLY nice Cutthroat in there. Below Waterloo bridge a ways down around the corner is full of cutts. Panther martin spnners and Size 3 Blue Fox or like spinner work well. You can keep fin clipped trout, but not the native cutthroat.
You may be able to do it. It will require some deep wading. I've done it before.
Best to just hop in a raft or boat. If you want to find good trout fishing, don't go to the obvious park areas and places where there is high fishing pressure.