It’s the best backcountry mapping tool on the web. The CalTopo app is a combination of map-making tools and real-time data that make it a great choice for your next trip. The app lets you access a variety of map layers from the USGS MapBuilder series, land management, sun exposure, fire activity, and custom terrain shading. The layers are available in both a flat and 3D view, allowing you to create and view different map projections.

You can use the app to plan your trip using its best-in-class map-making tools. The app will automatically sync between your phone and CalTopo.com in seconds, so you can stay up to date with the latest information. Once you’re in the field, it’s easy to sync your GPS track back to CalTopo.com in real-time, or drop markers and instantly share them with friends.