Stillwater is visually spectacular and there are tons of birds, if you’re in to that sort of thing. The road in is very well maintained and any vehicle should be able to make it, unless there’s snow. But if you’re looking to camp (like tent and sleeping bag), then this isn’t the place for you.
There are only two designated “overnight parking” areas, which are both next to the vault toilets. You could park an RV or a van here and be fine. But the only place to pitch a tent that’s not next to a main road is super loose sand. I can understand there being no fire rings being that it’s a wildlife conservation area, but there is zero demarcation of where you should pitch a tent.
Overall, cool place to visit and take pictures but not a great overnight destination.