Idaho big tree program

Idaho big tree program

There are many impressive things on this big blue ball we call home, but few surpass the magnificence of a soaring, magnificent big tree. Called the superstars of their species, champion big trees have been recognized by American Forests Champion Trees program since 1940. With more than 700 species in the champion trees national register (pdf), these big trees are found in the fields, forests, rangelands and urban parks, and yards of America.  

Idaho has participated in the Champion Trees program since the mid-1960s, with a shared mission of locating, measuring and recognizing the largest individual tree of each species. Idaho's registry of champion big trees (pdf) lists the current 117 State Champion Big Trees located across the state.

Today, there are many tree species without current national champions. The National Champion Trees program currently has a list of species without champions. There are also many species on the Idaho Registry that are larger than current national champs. Some of these reigning state champs may or may not be alive; many were also measured too long ago to submit for national status. We encourage the nominators of these trees to revisit their champions and resubmit updated information and photographs.

Big tree hunters are people of all ages and walks of life who share a love of one of nature’s finest accomplishments — a truly splendid big tree.

Champion tree status is awarded using a point system.  

• One point is recorded for each foot of height
• One point is recorded for each inch of circumference. Circumference is measured at the diameter at breast height 4 1/2 feet above the average ground level (dbh)
• One-quarter point for each foot of average crown width

To calculate a tree’s total point value, American Forests uses the following equation:

• Trunk circumference (inches) plus (+) height (feet) plus (+) 1/4 average crown spread (feet) equals (=) total points

The registered champion tree is the one in the nation with the most points. The tree with the most total points is crowned national champion.

When multiple candidates exist, the 3 x 3 rule is employed, meaning co-champions are crowned using the following criteria:

• If the trees are under 100 points and within three points
• If the trees have more than 100 points and the differential is 3% of the total

The final register is released each year in July. Champions listed in the national registry must be remeasured every 10 years to maintain their National Big Tree Champion status.

Idaho champion trees will retain their status until another nomination topples the reigning champ or the reigning champ dies.

Definition of a tree

The national big tree program defines trees as:

• Woody plants that have one erect perennial stem or trunk at least 9 1/2 inches in circumference at 4 1/2 feet above the ground (DBH)
• Definitively formed crown of foliage
• Height of at least 13 feet

Nominate a tree

Big tree nominations begin at the state level. The completed nomination packet is sent to the Idaho Big Tree program director, who verifies the information and tallies the points. If the nominee has enough points to challenge the current national champ, records are then forwarded to the national level by the Idaho director. 

To get started, measurements need to be verified in the field by a qualified forester. Please include GPS coordinates and photographs — they are required by both the state and national programs. 

Mail the packet to:

Idaho Big Tree Program
University of Idaho
875 Perimeter Dr. MS 1133
Moscow, ID 83844-1133

Because of recent changes to the National Champion Tree Program requiring champion trees to be remeasured every 10 years, there are many tree species that have no current national champion.