In the old days, we all navigated trails with the aid of USGS paper topo maps that show the terrain, waterways, and existing trails. With publicly available GPS signals today, anyone can purchase a handheld or vehicle-mounted navigation unit and use it for backcountry exploration.
Small handheld GPS units are compact but can be difficult to read when viewing terrain or topo maps in a vehicle. We've known off-roaders to use laptops or netbooks with GPS software to provide large, easy-to-read maps, but they can be expensive and bulky. Recently, the increased availability of tablet devices has further opened possibilities for in-vehicle navigation.
As popular as the Apple iPad and iPad Mini are for a variety of uses, only the cellular-capable models currently have Assisted GPS and GLONASS (Russian system) capability. The Wi-Fi-only models have no GPS receiver but can use an external one for off-road navigation.
We are currently using a Google Nexus 7 tablet for topo map navigation. This is a touchscreen Android-based 7-inch tablet with a built-in GPS receiver. We're using this $200 tablet with ViewRanger GPS software. It has the capability of recording tracks and displaying topo maps and routes you can load onto the device. With it mounted on the upper dash of our truck, it's easy to check progress on a terrain map as we travel off road.
Today we have an increasing number of great choices to use for off-road navigation and exploring. Consider checking out a tablet solution for your GPS needs.