I used google earth to trace the shoreline of my (large) lake, got a portion of the way through it and then got pulled away. I've loaded my shorelines.kml file back into google earth and I want to continue tracing the shoreline but I can't seem to find a way to continue where I left off. Am I missing something or is this not possible? To start over would mean repeating hours of work. Any help would be appreciated.

Your are missing something. :)

Right click on your shoreline in the menu on the left, choose properties. Leave the menu-box that comes up open, you can now edit your polygon.

Assuming you saved your shoreline, or still have GE open, you should be able to edit it again. Just right click on the object under My Places and select Properties. That should highlight the polygon and you can carry on inserting or editing nodes.

edit: Team Colibri beat me to it :)

Thanks guys!

One quick thing to add, once you have the properties window open, the points that define the polygon should show on top of the polygon line. If you hover over a point, it should change colors, slightly move that point a bit and release. Then draw your next point from there. This is how you start from an existing point.

Things can get screwed up here though if you proceed in the wrong direction (ie. clockwise or counter-clockwise) from the direction you were originally creating the polygon. If one direction, doesn't work, hit the delete key to delete your last erroneous points in order, and then proceed in the other direction from the next point over. If you're creating a ton of polygons, it helps to always choose a default direction of creation....but if you don't it's still easy to recognize after a couple newly created points.

Hopefully that made sense.