I would go to Cottonwood canyon/ JS Burres State park. There's a really convenient trail from the parking lot at JS Burres (on the south side of the river, not the camping side) that goes for a long ways down stream. It was the closest place I could find to civilization that had good access. There's a lot of private land that makes it hard to get to the river. My brother and I went out there last summer and lost count at 50 landed smallies. If it's soft plastic they'll eat it. I'm sure we hooked a hundred or more. It was like "oh you lost that one? There are 12 more right there!"
Edit: Looking at the map there's a trail on the north side too, so take your pick.