Georeferenced PDF maps contain embedded coordinates that allow you to track your actual location on the map. DEC uses georeferencing in many of our recreation maps as a public service that improves safety for people who enjoy outdoor activities on the nearly 5 million acres of lands we manage.
Once a georeferenced map is downloaded, you don't need cell service; you can use your smartphone's GPS system to pinpoint your location. You'll be able to see exactly where you are on a hiking trail or in the field, which will make finding your way that much easier.
You should always bring a paper map and compass when entering the woods - the batteries will never die on a paper map!
Not all maps contain georeferenced data - look for the (GeoPDF) tag included in the map link.