a not-for-profit in Washington, DC
has maintained the
National Register of Big Trees
for over 50 years.
American Forests has a 3-part formula—
based on girth, height and crown spread—
to rate a tree by size
and determine which is
the Champion—
the biggest.
The current National Register
lists over 800 tree species
with a recognized National Champion.
Eastern Native Tree Society
is an interest group of foresters, arborists and ecologists with a complex database of wooodland trees that ranks champions by height, volume, ecotone, and latitude. ENTS has developed reliable measurement methods accurate to one foot.
American Forest Owners
Association
maintains a separate database
of the oldest trees state-by-state