As
the article titled "Caltopo: A Great Online Mapping and Planning Tool for Hikers" describes: "
Caltopo.com is free to use. It supports many of the capabilities of desktop topographical mapping software but it’s online so you can access it anywhere and share it with other people. You can store maps you create with it for future reference, export and import gpx files, embed maps on a web pages or send them with a hyperlink. Caltopo also supports collaborative planning, like Gmap4, but the printing is much better."
"Caltopo was originally developed for search and rescue work by Matt Jacobs, who loaded it with California-specific mapping data. He later added data for the entire United States but the original name stuck."
Another interesting description of CalTopo, and where it is going, is in
this article that starts: "For several years my go-to platform for topographical maps and imagery has been CalTopo".
