Yeah, a lot of them. There are more along the Short Loop than the Long Loop, and there are several marked if you use All Trails. You don't have to register or pay for any of them, for up to two weeks. They can't be reserved, so it's first come first serve, but I've never had trouble finding an open one that's good for either hammocks or tents.
Yes free sites (dispersed camping) no registration required
Tons of spots.. large spots, small spots, medium spots. If you have ambition and want to haul some rocks for a fire ring you can even make your own spot. It's fairly free there.
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