Blight-resistant hybrid American chestnut trees protected by fences were planted here so scientists can study their disease resistance in a protected, semi-natural environment. This is one of several American chestnut test plots in Virginia. The National Park Service monitors the health of these trees and shares findings with the American chestnut restoration project team, which includes several universities, the U.S. Department of Agriculture Forest Service, and The American Chestnut Foundation. The team is dedicating time and energy to help restore this iconic tree. The B3F3 hybrid trees in this test plot are seventh generation and 94% American chestnuts. They retain many of the physical characteristics of the native trees while gaining the blight resistance of Chinese chestnuts. Starting around 1904, chestnut blight decimated the nation's hardwood forests. The fungal disease came from non-native Asian chestnut trees, and its spores spread on the wind, birds, or mammals at an alarming rate of 23 miles per year. By the 1950s, 8.9 million acres of American chestnut trees were dead or dying. Individual American chestnut trees have survived, but few grow to chestnut-producing maturity.