In Arkansas it's not illegal to live off grid.
If you want to live off grid in Arkansas it's completely legal unless you live in a town, city etc and in that case you may be required legally to hookup to the city utilities.
However if you live out in the rural parts of Arkansas and away from towns, cities etc then it's illegal to live off the grid in Arkansas.
You might be able to get by with living off grid in Arkansas in a small town or small city but if you live in a large town or large city then the codes can come into play if they have them.
The best way to live off grid in Arkansas and other states is to live away from towns, cities etc and live out in the wooded areas.
Then nobody will likely know about you living off grid and you can get by with it better there as well.
Also if you want to live off grid you'd be happier either way being away from neighbors.