Greasy Fork is available in English.
Adds GIS layers in WME
Ok, so this is only a couple years late. Sorry! I don't check the feedback in Greasyfork regularly and I don't seem to be getting any notification emails. I need to look into that...
I took a look at the county site and it uses a data format that isn't (currently) compatible with the script. It's a format that I've been wanting to add support for, but just haven't found the time to dedicate to it.
Douglas Co, Wisconsin GIS data source
This data source seems to be more updated than the source the script is using, I don't know if it has an API. It's the 'official' GIS map that the county and major city in the county link to on their official websites. http://douglascowi.wgxtreme.com/