The fox squirrels in MD are the Delmarva fox squirrels which are a different color than the Eastern Fox squirrels. The Delmarvas are grey and white and have no red on them and have white bellies not orange. Back in the early 80s there was an effort by the PGC to release captured wild fox squirrels in areas where they no longer existed. I got some to release and Middle Creek got quite a few released on the area. They squirrels came from western PA and I do not remember if any came from other states. Fox squirrels were more creatures of small woods and long tree lines than the grey squirrels that like big deep woods. When I was a kid we hunted fox squirrels in Lebanon Co where they coexisted with greys. We had about a quarter mile of hickory trees on a tree line fence row that produced a huge number of squirrels. It was not unusual to come home with a mixed bag of greys and fox squirrels. The are gone now along with the hickory trees. Any way, at first the fox squirrels that we released seem to be doing well, there were lots of sightings and hunters were bagging some where before they did not. However they seemed to have disappeared now.
When you are up to your butt in alligators, it is hard to remember your intent was to drain the swamp. Stay focused!