Roaring Fork Valley Phenology | October 7, 2013

ACES Staff

October 7, 2013

Roaring Fork Valley Phenology | October 7, 2013

Fall’s signature events are happening all at once right now. 

• Peak aspen leaf change in the high country around Aspen occurred around October first. This is toward the later end of when we expect peak to be. 
• Trees and shrubs in the montane zone (below 9,000 feet) are currently peaking. Cottonwood, chokecherry, oak and red-osier dogwood are especially vibrant right now. 
• The first big cottonwood leaf fall in town was October 3. Much more to come.
• The first snow in Aspen (according to ACES’ snow pool rules*) was September 29. 
• Bluebird days finally appeared during the end of September and first days of October. 
• The wild Golden Eagle returned to Hallam Lake doing fly-bys and interacting with ACES’ resident eagle.
• The pattern continues with more heavy wet snow followed by more bluebird days.

When heavy wet snow falls on cottonwood trees still holding most of their leaves, the trees may become overloaded and fall and or lose limbs. This same process repeats in the spring when we may receive late snow just after the cottonwoods leaf-out. In the next week leaves will be falling all over, Sandhill Cranes may be heard flying high overhead, and bears will continue to eat 20,000 calories of berries and acorns per day, getting ready for a long slumber.

~ Jim Kravitz, Director of Naturalist Programs

*contact Jim Kravitz at jkravitz(at) for full snow pool details.