Kayaking AloneThe Columbia and its tributaries are rivers of conflict. Amid pitched battles over the economy, the environment, and breaching dams on the lower Snake River, the salmon that have always quickened these rivers are disappearing. On a warm day in late May, Mike Barenti entered the heart of this conflict when he slid a whitewater kayak into the headwaters of central Idahos Salmon River and started paddling toward the Pacific Ocean. This account of his two