How old are the kids? How much time do you have? What sorts of things do you like to do? The answers to those questions will influence our recommendations.
Having done a lot of traveling with small kids, I would recommend keeping the drive time to a minimum. I think that the Bishop Creek area might be a good fit -- the campgrounds are at around 9000 feet, there is great fishing and hiking, and it is about 300 miles from home (95 to 266 to 168 to 395).
You will find that RVing with kids is a lot of work and is a ton of fun. We never got to do it -- our kids were grown by the time we discovered RVing, unfortunately. But our friends who have camped with kids tell us it is great.