Tree planting is one of the most lucrative summer jobs a college student can get, but it is also one of the most difficult. While veteran highballers can earn $15,000 or more per season, making that kind of cash requires long, lonely hours working day after day in some of the most inhospitable conditions imaginable. Bugs, bears, hailstorms, freezing nights, rocky ground, and grumpy foremen are just some of the hazards tree planters must face. But...