Oregon is booked. Now looking for boondocking

Hello. I should have listened when everyone was telling me that the Oregon coast campground fill up fast. I tried booking at Fort Stevens, Cape Lookout, etc. for August and they are all booked up.

If I can't find a full hookup camp site then maybe we can go boondocking. The RV has a generator and big tanks so we could "rough it" in comfort. I just don't know where to go. I live in Portland and would like to stay within 250 miles of home.

I was thinking that maybe some of you may be aware of some other camp grounds that would fit our needs. Any suggestions are greatly appreciated.

We have a 40' toy hauler.
A family will be camping with us in a tent so we need a camp site that is friendly to RVs and tents.
Lots of kids with us.
We would like to be close to the coast with beach access.
We do not have to go to the coast. We are flexible.
Looking for someplace fun for the kids.

Please ask questions if you need more info.

Thanks!!!