Elers Koch, a key figure in the early days of the U.S. Forest Service, was among the first American-trained silviculturists, a pioneering forest manager, and a master firefighter. By horse and on foot, he helped establish the boundaries of most of our national forests in the West, designed new fire-control strategies and equipment, and served during the formative years of the agency. Forty Years a Forester, Koch's entertaining and illuminating memoir, reveals one remarkable man's contributions to the incipient science of forest management and his role in building the human relationships and policies that helped make the U.S. Forest Service, prior to World War II, the most respected bureau in the federal government. This new, fully annotated edition of Koch's memoir offers an unparalleled look at the Forest Service's formative ambitions to regulate the national forests and grasslands and reminds us of the principled commitment that Koch and his peers exemplified as they built the national forest system and nurtured the essential conservation ethic that continues to guide our use of the public lands.