If you want to avoid drama you should look for a smaller boarding farm, I have never seen a large operation that does not have drama. How far south in St. Mary's are you looking? I boarded at Sam Hill Farm for a few years and it's a very quiet atmosphere, I accomplished a lot of training during my stay there because there was no drama. I shared the place with the owners and 3 other boarders and enjoyed my horse and training without the typical drama queens you find at just about every large boarding stable. Sam Hill is located in Charlotte Hall, right on the edge of Charles and St. Mary's counties.
They have an indoor and an outdoor dressage and jump area. When I was there the owner only turned out during the day, my only gripe because it was so hot in the summer sometimes. All pastures have a run-in shed and the stalls have fans and I found my guy stayed comfortable with those accomodations. Also, she didn't blanket so you have to take care of that stuff yourself or work with the other boarders. Otherwise she did everything else and my guy was very happy there.