Former national champion plains cottonwood. Credit: American Forests.

It was secluded in an old irrigation ditch at the bottom of a steep embankment, and many residents in Hygiene, Colo., simply called it “The Big Tree.” At 150 years old, it lived a life much longer than the average for its species, but time caught up with “The Big Tree,” as the biggest plains cottonwood in the United States has been pronounced dead by park officials after it was discovered that the tree produced no new growth this past spring.

The national champion tree first came to American Forests’ attention back in 1967 when it was nominated for the National Register of Big Trees by Allegra Collister, the Longmont Audubon member whose name now lends itself to the Allegra Collister Nature Preserve in Boulder, Colo. For 45 years, the cottonwood was on the National Register as the biggest of its kind. It’s easy to assume that a national champion will retain its status year after year, but with new competition, storms, diseases and pests, most champs are lucky to have a continuous run of more than five years. The plains cottonwood held its ground for more than four decades. Only a dozen tree species on the register have reigned for longer.

Plains cottonwoods are the largest broadleaf trees in Colorado, Wyoming and New Mexico, with an average trunk diameter of six feet. They generally have a short life expectancy of 70 to 90 years, with few trees rarely reaching a century old. The former champ surpassed the well-known traits of this cottonwood species by reaching 150 years in age and having a trunk diameter of approximately 11.5 feet. Our partners with the Colorado Champion Tree Program’s most recent measurements show the tree had a circumference of 432 inches, a height of 95 feet and a crown spread of 98 feet, giving it a total of 552 points. The second biggest plains cottonwood in Colorado is located in Larimer and has a total of 517 national points. With the demise of the long-running champion, maybe the tree in Larimer will become the new national champion with the fall update to the National Register.

“The Gentle Giant of Boulder County,” which received its name from a nearby sign in a viewing area, will be allowed to remain standing for as long as it can by Boulder County. Although, the tree will no longer be represented on the National Register, its fallen limbs will become a source of materials for woodworkers to craft artisan products — a way to continually celebrate the life of a marvelous tree.