Rio Grande is really remote and far from any supplies; There is a small, and
I mean REALLY small grocery store and gas close by but it is far from anything
else; The sites are essentially a large parking lot and rather unappealing.
Stillwell RV is just on the outside of the park but again really remote.
Personally, I'd stay at Terlingua - large grocery store, several restaurants,
close to the NP and closer to the State Park.
Gerry