Does this sound like a good book idea? TEN POINTS BEST ANSWER!!!?

Sounds familiar, but you can certainly add your own twists by reversing some of your plot ideas. Perhaps switch it up by having guys versus girls, or half must complete a scavenger hunt while the other half have to keep them from completing it. Remember, with GPS and satellite imagery keeping the authorities from finding 50 people is going to be hard, even in the desert. Even if they tell their parents they're on a field trip, someone out of that 50 will probably need to contact their kid for some reason.