I've been there multiple times and always found spots open.

There are 100’s of spots back in that area. There are so many roads that spider off from one another. Not all roads would be passable in all vehicles. Just scout them out first.

We were there in the middle of July, in the middle of the pandemic where everyone was out camping. The camping sites are very dispersed from each other and there was probably a dozen campers out there with us, spaced hundreds of feet apart. I wouldn’t call it busy, just active, but not full at all. 4WD will probably get you a little further out when the roads are wet or too rutted out.

It’s a huge area. I think it would be almost impossible to fill it all up.

I had no problem in June two years ago, before schools got out and the crowds came. Schools are back in session now, so the same should be true. Be aware though that many of the sites off the main road are not easy to get into unless you have a small RV and 4WD.