Finding aspens near Aspen: Fall colors hitting their peak around central Colorado

The aspens along Copper Creek on the Crested Butte side of the East Maroon Trail were in full color earlier this week. The 16-mile hike between Aspen and Crested Butte is easier but longer than its counterpart, West Maroon Trail.
David Krause / The Aspen Times

September in the Colorado high country is a time of year that would make Bob Ross jealous.

Led by the golden hues of aspen groves, the mix of colors above 6,000 feet are reminiscent of the “happy little trees” the late television artist would often mention as he worked his majestic landscape paintings on “The Joy of Painting.”

This week and through the end of the month are the prime times to see the color changes, according to many leaf predictors, in the Aspen-area and the surrounding Elk Mountains.

There are a number of avenues to enjoy the view, but central in chasing the aspen colors in this area is between Aspen and Crested Butte, either through hiking over on one of the Maroon Creek trails or via Kebler Pass.

While the pass is home to one of the largest aspen colonies in the world, the options to hike between the two mountain towns take you deep into the backcountry and away from the crowds.

Not to worry, though. A recent weekend trip hiking to Crested Butte from the East Maroon Trail and the drive back over Kebler Pass revealed there still is time to see the colors explode there and on McClure Pass.

The science of the leaf changing is dense, but the beauty of it is simple. Thousands of people are drawn to the Colorado mountains every September to see the populus tremuloides change from vibrant greens to powerful yellows in the autumn sun.

With this year’s drought, there were concerns about a dry summer’s effects on the aspens, but it is more about the change in timing than in colors, says Colorado State Forest Service forester Jeff Underhill.

“In the short term, a drought causes the trees to shut down earlier than normal and shut down the chlorophyll production earlier,” says Underhill, who worked for the U.S. Forest Service for nearly two decades. “As for long-term effects, it really depends on if it is a drought for one season or a prolonged drought event lasting years. That’s when the trees can become more stressed and susceptible to insects and disease.”

This year, Pitkin County was listed in the moderate drought category on May 1, but through the summer the listing has crept up, and by mid-August the entire county was listed as in an extreme drought by the U.S. Drought Monitor. Many wildflower observers in the area noticed the peak of that season was early this summer.


The aspens have been turning in the past few weeks at the higher elevations and cascading down the valleys. The big colors on the east side of Independence Pass started earlier this month and were followed last week around the Roaring Fork Valley.

“Elevation is one of many factors,” Underhill said of when leaves will turn. “Usually, aspens do best at 6,000 to 11,000 feet or slightly higher. … Where elevation comes into play is when leaves turn color. Higher elevations get colder sooner, and chlorophyll production shuts down sooner.”

Maya Hunt with the Aspen Science Center moved here three years ago and was instantly inspired by the golden aspens. She put together a piece on why chlorophyll is green and how it relates to kind of light emitted by the sun. She delved into the photosynthesis process here on Earth and beyond.

Using her degree in astronomy and physics, Hunt took leaf colors out into the universe to project what plant life on different exoplanets could look like based on the kind of star they evolved around and the color of light it would emit. Hunt grew up in Oregon, went to school at the University of Pittsburgh and worked in Rhode Island, so she has plenty of experience being in nature.

“It comes down to when it is most efficient for trees to stop creating chlorophyll,” she said. “When using more resources than it’s worth is when they go dormant and go to their base colors, which for aspens is the golden yellow.”

The stunning colors likely will remain for another week around Aspen (elevation of 7,908 feet) and joining them in the coming week or two will be the aspen colonies off to the south and west. The aspen-covered valley along Kebler Pass in the lower elevation between Marcellina Mountain and West Beckwith Peak and East Beckwith Mountain still was more green than gold over the Sept. 15 weekend.

According to an interactive map put together by the rangers at the Smoky Mountain National Park to track the entire United States, the peak for colors around Pitkin County and central Colorado begins this weekend and hits full-on into the week of Oct. 1.


In the backcountry, the East Maroon Trail is the longer and more direct of the Maroon trails between Aspen and Crested Butte; West Maroon is about 5 miles shorter, but steeper and most say more scenic for flowers and tree changing.

But often there are more pikas than people on the 16-mile East Maroon trek coming from the Aspen side, especially before the 11,800-foot summit of East Maroon Pass. After that, it’s hikers who start near the town of Gothic and are arriving at Copper Lake who you encounter.

The trees on the Aspen side were still making that chlorophyll last weekend, but on the Crested Butte side of East Maroon Pass along Copper Creek things were in shutdown mode, bringing out bright yellows, golds and even some reddish-orange aspen trees.

The best way to find the peak colors you seek is to hear local observations from those around town and the locals who know the trends, Underhill suggests.

As with each season in the high country, there are those who have a passion for a certain time of year. And for Hunt, autumn comes down to a simple thought: “I just love leaves.”