I also explained how to update Nuvi gps systems with Lifetime Maps in this tutorial .
At OSM maps are free, created and updated by users and volunteers across the words.
If you've purchased one of Garmin's many GPS units that offer free map updates, you will choose this map updates page, which will prompt you to download and install the Garmin Express map updater utility, if you don't already have it installed.
Follow the instructions to get Garmin Express running on your machine.
Trail maps from GPS Trailmasters will " See our Installation Guide for how to install our maps from the download or purchase a pre-loaded micro SD card for plug-n-play insertion into your Garmin GPS. Try "Satellite" view to test the accuracy of our trails! Plan a route or select a destination and get turn-by-turn directions displayed on your GPS. Monitor the "Time to Turn" and see the turn indicator displayed on your GPS.