Arkansas State Park recommendations and things to see

All the Arkansas State Parks are very good. We like Lake Dardanelle

Very close to Hot Springs you will find Lake Ouachita, Lake Cathrine and Lake Degray. All have beautiful camping spots and will handle your 30 footer with no problem. They are anywhere from 5 to 30 miles from Hot Springs.
Crater of Diamonds state park near Murfreesboro, Arkansas is a very nice place and as already said, you can dig diamonds and keep them as well as other semi precious stones that you find. There is a small fee to do the digging.
Crater of Diamonds state park is about 60 miles from Hot Springs.
Hope this helps.

We really enjoyed the Buffalo Point State Park.

Just a little further away than Petit Jean is Queen Wilhelmina and Devil's Den. Both have lots of trees and great hiking. There's also Crater of Diamonds, lots of trees, not much hiking but you can keep all the diamonds you find. At the south base of the mountains near Queen Wilhelmina is a small campground called Billy Camp. It's hard to find, not on many maps and probably a bit small for a 30' rig - it's mainly a tent campground without hookups but it's a gem. Wooded, with a steam running thru it and right on the trails that go all the way up into Queen Wilhelmina.

Petit Jean
Mount magazine
Wooly Hollow
All are great places to stay.

All Arkansas state parks are good but my favorite is Petit Jean. Nice campground with great hikes but nothing else in the area