GPS LAND NAVIGATION is an essential book for backcountry GPS users. It provides thorough coverage of how the global positioning system works, & how a GPS user can get the most from his/her receiver. It contains important information about the limitations of GPS receivers, including the dangers of using 2D mode (something you probably won't find in your receiver's manual, & don't want to discover for yourself in the field). Topics include clear explanations of how maps, coordinate systems, & datums work, & how to use them with your GPS receiver. GPS receiver functions are explained in easy-to-understand terms, in ways that apply to backcountry travelers. Current models of GPS receivers are compared. Other kinds of land navigation & GPS-related equipment such as compasses, altimeters, & map reading tools are also covered. Extensive coordinate listings are included: the highest summit in every county in the United States, & all U.S. Interstate/U.S. Highway intersections. GPS LAND NAVIGATION is well-organized, extensively cross-referenced & thoroughly indexed, making it easy to find specific information. It includes over 150 illustrations that visually demonstrate the subject matter. Order from: Glassford Publishing, P.O. Box 2895, Boise, ID 83701-2895. Phone (208) 343-9205, e-mail order@glassfordpublishing.com.