» Research with Google Earth
This free mapping software can pinpoint locations, has up-to-date road and landmark data, and provides a resolution of one square meter per pixel–enough to discern tent-size clearings and gravel roads–for most of Earth’s landmass. View 3D details of terrain like cliffs and ridgeline angles around the globe, and you can use the sunlight tool to find sunrise vantage points. Go to backpacker.com/mapoverlay for a tutorial on how to overlay traditional topos onto Google Earth’s 3D projection, which helps with interpreting foreign-language maps. Of course, it’s impossible to accurately assess hazards like snow or raging rivers from an armchair.
» Find rare maps
The most detailed international topos come from the National Geospatial-Intelligence Agency, the Russian military, and Swiss surveys. Land Info (landinfo.com) has country-by-country datasheets outlining topo availability, and you can custom-order high-resolution satellite flyovers to get specific images. Researchers at the American Alpine Club’s library (americanalpineclub.org) will track down rare maps and expedition trip reports—and digitize maps—for the cost of a $75 membership.
» Use navigation apps
BACKPACKER Map Maker Plan foreign routes on your iPad by toggling between satellite, topo, or any two of five map types with our app’s dual-mode tool. Bonus: Trips at home or overseas sync seamlessly with GPS Trails, our smartphone app, so you can access your adventures anywhere. ($10; backpacker.com/mapmaker) PDF Maps Cache this app’s 6,200-plus maps for offline access, so you can navigate without pricy data plans. Beware: International coverage is spotty—you get super-detailed topos for New Zealand, but only street maps for South America. (free; avenza.com/pdf-maps)