Some believe the tree goes back to a single seed that took root after the last ice age more than 10,000 years ago, and it has been sending out replacement suckers ever since.

The tree’s seeds are blanketed by thin white floss, sort of like a dandelion, allowing them to hitch a ride on the breeze away from their parent tree, perhaps to somewhere they might take root.

Unlike most deciduous trees, trembling aspen can photosynthesize through their bark, even in winter. Big-toothed aspens look similar, but as their name suggests, their leaf edges are serrated.

Construction takes place among a pile of discarded cottonwood tree parts at Barr Lake State Park in Brighton on Friday, Sept. 22, 2023. Environmental groups are worried about the removal of cottonwood ...