The Global Positioning System, or GPS, is increasingly the tool of backcountry travelers.  This pack-sized book is a guide to practical field use of GPS for anyone whose play takes them to remote or hard-to-find areas.  Bruce Grubbs, vetern outdoor writter and technology enthusiast, offers helpful advice for hikers, backpackers, anglers, mountain bikers, kayakers, canoeists, and cross-country skiers.  Written in simple language, with each term explained as it is used, Using GPS is a wealth of useful backcountry navigation advice for beginners and experts alike.