Cottonwood trees in autumn Edness K. Wilkins State Park, Wyoming. Photo by madpoet_one / Flickr (noncommercial use permitted with attribution).
Official State Tree of Wyoming
Wyoming designated the plains cottonwood as official state tree in 1947. The statute was amended in 1961 to change the scientific name to: Populus deltoides variety monilifera. All State Trees
Plains Cottonwood Facts
The plains cottonwood is a large, fast-growing, short-lived tree of the Great Plains and eastern border of the Rocky Mountains. Members of the willow family, cottonwoods are named for the cotton-like mass of hairs surrounding their seeds. They are related to poplars and aspens.