SHOT 10/3/14 11:22:02 AM - Trunks of aspen trees along Kebler Pass just outside of Crested Butte, Co. Aspens are trees of the willow family and comprise a section of the poplar genus, Populus sect. Populus. The Quaking Aspen of North America is known for its leaves turning spectacular tints of red and yellow in the autumn of the year (and usually in the early autumn at the altitudes where it lives). This causes forests of aspen trees to be noted tourist attractions for viewing them in the fall. These aspens are found as far south as the San Bernardino Mountains of Southern California, though they are most famous for growing in Colorado. Autumn leaf color is a phenomenon that affects the normally green leaves of many deciduous trees and shrubs by which they take on, during a few weeks in the autumn months, one or many colors that range from red to yellow. The phenomenon is commonly called fall colors and autumn colors, while the expression fall foliage usually connotes the viewing of a tree or forest whose leaves have undergone the change. In some areas in the United States "leaf peeping" tourism between the beginning of color changes and the onset of leaf fall, or scheduled in hope of coinciding with that period, is a major contribution to economic activity.
(Photo by Marc Piscotty / © 2014)