Published: Aug. 7, 2019

Annual maintenance of the “Old Main Cottonwood” tree will require a crane and cause some pedestrian impacts in the Norlin Quad for most of the day on Monday, Aug. 12.

A contractor will conduct the removal of a few leads in the canopy of the tree that have died over the past year. Work will begin at 7 a.m. and last eight to 10 hours. Sidewalks and other walkways on the south, east and west sides of the Old Main building will be closed to ensure safety, and pedestrians and cyclists are encouraged to use alternate routes on this day.

The 140-year-old Old Main Cottonwood sits on the south side of Old Main, and was one of the first trees planted on campus after Ƶ Boulder sprung up on what was then a nearly treeless landscape. The plains cottonwood is both the oldest and tallest tree on campus, standing at 110 feet.

The campus arboriculture team oversees annual inspection of the tree—along with dozens of other aging trees on campus—to ensure structural integrity, maintain its health and remove dead or dying limbs that may pose safety risks.

Regarding the upcoming removal of dead limbs, Ƶ Boulder Arboriculture Manager Vince Aquino said the balance of the crown “appears to be live and appropriately vigorous for this species and age.”

In 2014, Aquino’s team partnered with managers of the campus’s Ecology and Evolutionary Biology Greenhouse to clone the tree by taking cuttings of the tree and rooting them. A few of those clones have survived and will someday be planted on campus to keep the legacy of the Old Main Cottonwood lasting on campus for many decades to come.