There are two cottonwoods in SB, this one is more common in the back country. The two may be distinguished by the shape of the leaf, the edge of the leaf for this species is serrated, while the other has a smooth edged leaf.
The name “Cotton”wood comes from the fluffy white puffs that attach to the seeds when ripe.
Cottonwoods are deciduous trees with the leaves turning to bright yellow in the fall and then dropping. In 2015 leaf buds had appeared in January.
The leaf of this species has a serrated, or lobed edge. Compare to that of Black Cottonwood with a smooth edge.