There is only one file type that uses the .OVR extension:
The Overlay Maker Overlay File
Drawing overlay file created by The Overlay Maker, a program used for annotating maps; supports drawn objects such as text, icons, and other vector and raster graphics; stores references to drawn resources and the map, but not the resource files themselves.
Overlays can be packaged into an .OVP package, which contains the overlay information as well as the actual resource files.
|The Overlay Maker||Free|
Updated: June 11, 2011