Jim,

Let's assume worst case where you don't have a map. Let's also assume you don't have a clue which direction your vehicle is in.

You are going to have to set up a search grid from a central point you can find again. Look at the terrain and rule out obvious directions.

Then decide on how far your truck could be from that location.

If you are good with a compass, you can do squares around the central point. If you aren't so good, you will probably have to do radials from the central point.

A GPS won't save you in this situation. Last week, I marked a waypoint right at the car when I left it. When I came back, the GPS showed me 600 yards from the car.

Someone who only takes their compass out a couple times a year is not an "expert." They may be good enough to be safe, but they are not an "expert."

Someone who is good with a compass ought to be able to navigate compass only with an error of 150 feet/mile. An expert should be able to navigate with an error of 50 feet/mile.