Since 1940, big tree hunters have hiked woods and trails — and backyards, cemeteries and college campuses — to find the biggest trees in the nation, then measure and nominate them for the annual American Forests Champion Tree national register.

In 2014, an American Forests’ advisory team, led by Don Bertolette and Bob Leverett, upgraded the methods used in measuring champion trees to better align with the needs of scientific research. The team created the American Forests Tree-Measuring Guidelines handbook, and American Forests’ previous three-page public guidelines grew to an eye-popping 86 pages of detailed instructions, designed to cover every measuring situation.

The team also recruited advanced measurers capable of meeting the challenges of accuracy. For decades, timber managers have measured trees for commercial volume, but the methods used are inadequate for the kinds of complex forms that characterize national champions. A new breed of measurer was needed.

Bertolette proposed the formation of a National Cadre, whose members would be competent in all methods presented in the measuring guidelines. Cadre members function as an elite unit to be called on to certify champion trees that presented special challenges to getting accurate measurements.

The Cadre was initially formed from individuals in the Native Tree Society and several state big tree coordinators who had developed advanced measuring skills. Each recruit agreed to cover a geographical area, which could be as small as a municipality or as large as a multi-state region. The Cadre is empowered to certify trees nominated to the national register and to assist state coordinators when requested. Beyond competency with all measurement methods in the guidelines, some Cadre members also function as trainers through workshops, distance-learning courses and one-on-one training.

American Forests maintains the national register of Champion Trees and works to protect the forests where our champions live.