Lower Bidwell Park
If you are looking for something a little more private, but still easy to get to, look no further than Lower Bidwell Park. Big Chico Creek runs through the entire length of the park and many of the picnic areas along the drivable path are close to excellent swimming holes. Finding an open spot can be difficult on the weekend in summer, so make sure to either scout out ahead of time or be flexible and willing to spend time searching for a spot. It is worth the effort.
There is parking available at each picnic area, trails to explore, some rocky beaches, plenty of shade trees. and many kid-friendly, shallow, places to dip into the water,