Colorado State Forest Service entomologist Dan West says the first reports of yellowing aspen leaves started in mid-August. By late last week, as sightings of possible fall foliage continued across ...

Nicole Craig of Columbus saw these aspen trees turning color while on a hiking trip in early October in southwest Colorado.

Aspen forests help slow the spread of wildfires and could serve as fire breaks in Colorado and other southwestern states, according to a peer-reviewed study by Western Colorado University researchers.

Rocky Mountain National Park, located about an hour outside of Boulder, Colorado, offers visitors ... noting that the Aspen ...

For the past 15 years, Luke Painter has been traveling to the northern range of Yellowstone National Park, where mountains rise and tributaries carve valleys of sage, willows and trees. This includes ...