The area is very big with hikers so they have a registry you have to fill out at the start-point where you give them your itinerary and they record details of everyone in the party (down to pack colours, etc). I also plan to leave a copy of the route and contact details of the registry office with my wife.
Now that is a place that has thought things through! What a simple and great idea.
Glad to see that you are very prepared for this!