Ed Quillen, columnist for the Denver Post and publisher of the very fun Colorado Central Magazine, has a nice little post on the High Country News Goat Blog. In the post, he gives a great little nutshell natural history of the Aspen, including its tendency to turn yellow in the fall.
Actually, Ed informs, an aspen's leaves are always yellow, or even orange -- they just look green in the summer from the chlorophyll activity. So in the autumn the trees are merely proudly sporting their true colors.
For which we are all most thankful.
Read that and more cool facts about aspen in Quillen's post here.