You could: Track down the company currently advertising on the sign and ask who they bought it from. Call some local billboard vendors in the area and ask if the board belongs to them. Call a national billboard vendor that owns a nearby sign and see if they own this one as well or if they know who owns it.
In the Commonwealth of Massachusetts, along winding highways, interstates and surface streets, billboards make an impactful statement. The Massachusetts billboards cut through the clutter and deliver an important message across to different demographics.