David leaned down to check his pack. Food, water, hammock, poncho, first aid kit, map, compass, GPS... he should have all he needs. He wanted to travel light.Fed up with the hustle and bustle of London, he had taken the opportunity of his 18th birthday to ask for a plane ticket to Yellowstone. If anything had cemented his need to get away from the modern world, that trip had done it. Heathrow airport to Atlanta: layover, customs, crowds, throngs of travelers moving like zombies; Atlanta to Chey