Namdu Sherpa picked potatoes as a girl in Namche Bazaar, the only economy in her village before Mount Everest-bound adventurers made a habit of trekking through with their Gore-Tex jackets and titanium walking poles. Almost overnight, the 75-year-old great-grandmother said, her small trading post in Nepal's Khumbu Valley transformed into a bustling tourist hub of lodges and cyber cafes. Nodding toward her gleaming Samsung refrigerator and microwave, Namdu Sherpa said life has changed dramatically from the days of tending crops and cooking over firewood. Through the years, though, one thing remained constant: the majestic snow-capped Himalayan mountains. Until recently, that is.