Examples of NTS map sheet identifiers are '011K' for a map at 1:250,000 scale, and '011K02' for a map at 1:50,000 scale. I also downloaded the topo maps for Utah. No more flipping back and forth between two different mapsets for street maps and topo maps. Even had all the streets of a new subdivision that just opened up the road from about a year ago. Way more topo detail, and way more up to date on roads than the Garmin topo maps. If you're serious about getting the most out of your GPS, check out the free trial of ExpertGPS, the ultimate mapping software download for your Garmin eTrex 30 GPS.
ExpertGPS also lets you view your GPS data over topo maps, aerial photos, and your own scanned trail maps.How to add and install topo maps in garmin basecamp for free Link: To Donate Garmin TOPO GB pro mapping is 1:25k, 1:50k and 1:250k mapping for both your Garmin Outdoor GPS unit and also for planning.