Prior to airplanes and severed mineral rights a person owned "to the heavens above and to the depths of hell!
As far as I know this hasn't really changed, but it's been awhile since I studied it and there has always been "grey area" with it as far as the air.
In the United States, the Federal Aviation Administration (FAA) has the sole authority to regulate all "navigable airspace", exclusively determining the rules and requirements for its use. The prevailing understanding is that a property owner can claim airspace that they are actually using (e.g., the trees and building structures on your property that occupy “your” airspace), but all other airspace is regulated by the FAA.
It's kind of like a right-of-way. The landowner "owns it" but doesn't get to regulate it. It's basically the same thing as you actually owning to the center of the street past your front yard, but can't build anything on it, block it, etc. and aren't responsible for its upkeep.
As much as I'd love to shoot the thing down a curb stomp it into pieces, I'd just report it to the FAA and Game Warden since it was on WMA property.