Where did your parents get this turtle? A lot of states don't allow you to keep Easterns anymore, and since Easterns are your state reptile it may have protection. You might want to check into that. And if they found it near a road it should really be let go where you found it since their numbers are really dwindling in the wild. Just some things to think about...
I live in the middle of box turtle country too. We are still allowed to keep them in my state (up to 5 may be kept which means someone like me is deterred from breeding, plus they are not allowed to be sold so you have to go out and catch one if you want one, you can't buy one from a breeder, but you can go out and kill dozens of most turtles per day in my state for food for crissakes).
We still have lots of box turtles here where I live though- you see them dead and alive on the roads all the time here.
What really irritates me- Urban sprawl and paved roads are really the killers when it comes to these turtles. Not a kid here and there picking one up for a pet. But it's easy to point the finger at the occasional kid.
If I drive an hour or so I can go back to my hometown. Semi-boggy fields where I used to find lots of box turtles as a kid are now k-mart, wal-mart, a mall, a mega-theater, a lowes, shopping centers of all sorts, a huge post office, etc, etc, etc. Their habitat for several miles has been paved over.
Makes me angry when politicians OK that kind of thing on the one hand and say a kid cannot pick up a turtle for a pet on the other...
Save a turtle or two from a kid and destroy their whole habitat so we can have walmart and a mall and home-depot and a best buy...
Sorry- I know this is off topic.
To the OP- get some metal or pvc roofing and make a pen outside- dig down a couple of feet and sink the roofing to make a little fence that goes a foot or two above and below ground so your turtle cannot climb or dig out. There is a lot of information available on the internet about how to construct an outdoor pen and how to take care of your turtle. You really should google it. If you do decide to release your turtle he needs to go exactly back to where you found him- they do not do well if released into unfamiliar territory.
Especially if it's a young one!! Box turtles are masters of escape. I watched one scale a vertical 3' chicken wire fence and plop out the other side. Make sure the wall is smooth, at least twice as tall as the turtle is long and there is nothing against it they could use to get leverage to climb out. There are lots of options! Remember they need lots of UVB and a period of hibernation in the winter. Outdoors would be best imo.
