Evan Welsh '06, center, discovered the largest oak tree in the United States in California's San Bernadino Mountains. Using tape measures and lasers, Welsh and a team of Wildlands Conservancy members took the tree's measurements—499 inches (41.5 feet) in circumference, 97 feet tall, with an average crown spread of 98 feet—and submitted the specs to the American Forests National Big Tree Program, which bestowed its offical certification as a champion tree.