Google Earth Integration
This article and much of our Knowledge Base now lives at the CalTopo training site. This specific page can be found here. Please go there for the most up to date information, as well as more comprehensive instructions for using CalTopo.
CalTopo makes it easy to do your trip planning side-by-side in both your browser and Google Earth.
Before getting started, it's important to note that CalTopo makes a distinction between exporting the data you've added to a map, and exporting images, whether those are plain basemaps, or basemaps with your data drawn on top of them.
There are two ways to get your data into Google Earth from CalTopo. The first is to export a KML file via Export and then Download KML File; this option is available whenever you have data (markers, lines, polygons) on the map. You can also pick and choose which objects are exported.
The second option is called a network link, and is only available on saved maps. The network link is a small file that tells Earth to keep requesting new KML files once every 10 seconds, so that it will automatically update to show the latest version of your map. Draw a line in CalTopo, switch over to Earth, and your line will appear in a few seconds. Data is only sycned one way; lines drawn in Earth will not automatically make their way back to CalTopo.
Below is an example network link; CalTopo's folder structure is reflected in Earth and you can turn individual folders on and off.
The best way to load basemaps into Earth is through something called a super overlay, although this is only available to CalTopo pro and desktop subscribers. Super overlays allow you to fly around in Earth and have the basemaps automatically update, without having to deal with fixed-boundary exports.
For convenience, any map's network link you download from CalTopo will automatically include superoverlays for CalTopo's base layers, custom layers that have been saved to the map, and layers tied to your account. You can turn these on and off just like any other objects in the Earth left bar.
The addition of CalTopo map layers can greatly expand Google Earth's trip planning utility. The following screenshots show trail locations near Yosemite Falls, and elevation contours on Mt Shasta.
If you just want access to super overlays, without going through a saved map's network link, click on your account name in the left bar, then the Your Account tab.
at the bottom of that dialog is a link to a KML super overlay file. The 6 digit ID in the filename is unique to your account; please don't share it.