I couldn’t get the maps showing Brian Olson’s plans for CA and TX to work on Google Maps because they were too large ~8MB. It turns out that Google also has a zip version .kmz that reduces those to about 2MB and they work now. I also changed the color to a tranparent shade so the underlying Google Map features show through. These are the URLs to paste in the map search box – remember that the extension is .kmz - not .kml
http://www.nautilusone.biz/redistricting/olsonMaps/caDistricts.kmz
http://www.nautilusone.biz/redistricting/olsonMaps/txDistricts.kmz
