 There are hundreds of large (2 to 5 ft diameter) American chestnuts outside its historical range, some in areas where less virulent strains of the pathogen are more common, such as the 600 to 800 large trees in Northern Michigan.The species is listed as endangered in Canada as well as in the United States.Chinese chestnut trees have been found to have the highest resistance/immunity to chestnut blight, therefore there are currently programs to revive the American chestnut tree population by cross-breeding the blight-resistant Chinese chestnut with the American chestnut tree, so that the blight-resistant genes from Chinese chestnut may protect and restore the American chestnut population back to its original status as a dominant species in American forests.