I have a Garmin GPSmap 60CSx, and I've found some aftermarket SD chips that show GMU's , property ownership and some other neat information. Does anyone have experience with any of these? I'm dinosaur enough that these are over my little head but I like the idea and what a great aid to avoiding trouble. Their are several available with all kinds of options, thus I'm confused about which one to buy. I purchased one from the Wyoming Game and Fish, bad news is it only works with Magellan. In the meantime, our new Chessie pup ate the box enough I can't return it. Somebody want a deal on that one? Thanks for any help, Steve.