Additionally, CalTopo is a powerful tool that probably has many other potential uses for you. If you need custom maps, I consider it worth the subscription cost. Update: You now need a CalTopo Pro account to create custom maps this way. In this guide I’ll show you how to create the maps, download them to your Garmin, and view them in Google Earth to visualize the topography. Today, using CalTopo, creating custom maps is dead easy. Custom maps have been available for Garmin GPS units for quite some time, but the process was clunky and tech-heavy. It means that you don’t necessarily need to buy a Garmin GPS with maps included, and it also means that you can create highly customized maps based on your use scenario. When you use the CalTopo website, these custom maps can be almost anything that you can imagine. If you have a Garmin GPS unit, you can create and download custom maps onto your unit. Using Basecamp to Plan With Custom Maps.Downloading a Custom Map to Your Garmin GPS.Creating a Custom Map To Fit Your Needs.How to Create and Download Garmin Custom Maps In This Guide