Are there areas within the park where kids can swim or wade in the river? If not are there other areas to swim close by?

I wouldn't use the docks or ponds the water is dirty and they are well fished with lots of lost hooks and line. If you park facing the bathrooms at parking lot 4 go to the right trail. Follow the trail until you come across where you can turn left on a dirt trail with a metal pipe in the ground keep going until you see the sign on the right with a small dirt path climb down and you will be at a beach like area where people swim a lot with out much fishing.

Yes, there are a couple docks.

I have seen people wade in the pond close to the main parking, I personally wouldn't, I don't feel like the water is good, too stagnant