How do you join paths on Google Earth?

In edit mode of google Earth you could take one point of one line segment (path) and extend it to the intersect with other line such that the two lines appear to be a single line. However, there is no automatic way to merge the two lines into a single feature.

To merge two paths into a single Placemark you need to manually edit the raw KML and move/copy the coordinates of one into the element of the other line.

Here's an example with a KML file having two line paths which need to be merged.

OLD KML:

east

-122.431885303019,37.8019316061803

-122.431762847554,37.8019476932246

-122.431719843168,37.8017374462006

west

-122.431719843168,37.8017374462006

-122.431841863906,37.8017213314352

-122.431885303019,37.8019316061803

The merged KML would look like this

east-west

-122.431885303019,37.8019316061803

-122.431762847554,37.8019476932246

-122.431719843168,37.8017374462006

-122.431719843168,37.8017374462006

-122.431841863906,37.8017213314352

-122.431885303019,37.8019316061803

Note when you manually paste the coordinates it's hard to debug and identify which points on the map are in which order in the list. To help debug editing the points a free online is available to generate numbers corresponding to the order of the point in the list. Click on related link below and paste your KML into the form.