Engineering EdenIn the summer of 1972, 25 year old Harry Eugene Walker hitchhiked away from his family's northern Alabama dairy farm to see America. Nineteen days later, he was killed by an endangered grizzly bear in Yellowstone National Park. The ensuing civil trial, brought against the US Department of the Interior for alleged mismanagement of the park's grizzly population, emerged as a referendum on how America's most beloved wild places should be conserved. Two