Wild Lands of the West | The BLM, National Geographic Magazine: Aspens In San Juan Mountains

Brilliant yellow leaves of trees light by sidelight from sun with snowy mountains behind with purple cast.

Evening sun kisses the tops of aspens as fresh snow arrives on the peaks of the San Juan Mountains near Ouray, Colorado.

The landscape of the Rocky Mountains is renowned for an amazing display of fall colors that last only a week. Catching a view of the aspens’ golden colors at the peak of the season can be a stroke of luck. The brightest autumn colors are produced when dry, sunny days are followed by cool, dry nights.

Aspen propagate primarily by sprouting from an expanding root system, which creates groups of trees, or clones, ranging in size from several trees to many acres. These clones are genetically identical.