For those of us who own Garmin GPS units and/or have purchased and have loaded on our computer the Garmin MapSource map programs (like the 1:100k series, 1:24k series, Natl Parks-West series, & etc..), Garmin does periodic software/firmware updates to these. It is important that you check-in to the Garmin website once in a while (I try to do it ~every 3 months or so) for any updates to your unit and/or to the MapSource map(s) series you may own.
For Software/Firmware updates to your Garmin units: http://www8.garmin.com/products/webupda ... nstall.jsp
(more applicable to newer Garmin models unless you have never or seldom updated your older Garmin unit)
For Software updates to the various MapSource map series you may own: Open on your computer MapSource, then go to the top of the page and click open the "Help" icon, then click on “check for software updates” and if any, load. (In the past two years, I have noted at least two major software maps updates-enhancements that Garmin has made to the map series that I personally own).
Hope this will be as helpful and beneficial to you as it has been for me..
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