I used to live in Maryland and the ONLY lake I know of that allows gas motors is Deep Creek. You should go to a marine store and get a copy of the Md watershed rules, I think it states in there that only trolling motors are allowed. I fished Liberty with a guy one time and he had a 16' Lowe with 4 golf cart batteries (6 volt) hooked up so they equaled 2 12V and we went all day on those. The only other water I know of are the tidal rivers (potomac, anacostia, choptank, etc).
I fished Rocky Gorge a lot back then and there were a lot of bass boats all with the big motors out of the water using their trolling motors.
Good Luck,
Al