Written by Michael Shostak
CalTopo is an online web application to create topographic maps for anywhere in the United States or parts of Canada. This app has been primarily focused on hiking maps but has added more advanced analysis in recent years. As an avid backpacker that likes to visit less frequented places, Caltopo is great for creating maps that are not produced commercially or even to save money on maps that are available for sale. There is never a reason to leave home without a map for your hike now.
The user interface when first arriving at the site will feel very familiar to those with GIS experience but also is quite friendly to those without. CalTopo uses layers to display data and has a number of preset layers that cover the entire country. The initial MapBuilder Topo layer is the most useful for creating maps that use trail and road infrastructure. To start your line simply select the +Add New Object from the table of contents and select from the available functions, markers (or points) and lines will be the most commonly used but a number of other options are available. My favorite part of this app is the snapping feature. When creating a line on a current trail or road simply hover over the starting point and the trail will become highlighted, once you click the line will then snap to the existing roads and trails as you follow along.
Importing and exporting is another useful tool that adds value to this platform. Imports are limited to GPX, KMZ, and KML allowing you to bring in lines and points that have already been created and show them on the map. Exporting adds in the ability to connect with a Garmin via GPSIO or to save as a georeferenced PDF using the print option. These PDFs can be printed or brought into any number of other applications for use on your phone while in the field. In addition, a GPX file can also be made for lines and points that you create in CalTopo.
While creating lines can be a little glitch, overall this app offers incredible value to users at the free and premium levels. The extensive base layers offer data like land management, fire history, sun exposure, slope, and SnoTel site information brining the scope beyond just hiking and into some analysis. From a cartographic sense, the finished maps do not offer much from a design perspective and suffer from some labeling issues and lack of other cartographic choices but from the functional side these maps are great for their purpose. Having paper maps could save your life someday and this app makes it easy to create them for anywhere in the US, free of charge.
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