Summit County's forecast for this weekend, sunny with highs in the 60s, offers the perfect temperatures for viewing the changing colors of the High Country foliage - seize the moment. This fall has showcased a spectacular display that is near its peak, scientists from the U.S. Forest Service say.
The first snow fall will cause most of the leaves to drop, so time is running out to see the beauty of fall in the mountains.
Boreas Pass Road in Breckenridge is a great place in the county to see aspen in their fall splendor.
Amateur photographer Cynthia James from Littleton said that she has been searching for the best fall displays in Colorado and "Boreas Pass is a must."
"Since moving to Colorado I've been scoping out places for pictures and Breckenridge is a great place to see fall colors right now," James said.
James, who was taking photos along the pass Thursday said "The fall colors aren't full fledged quite yet, but they're sporadic enough to see them across an outlook areas - it's only going to get more beautiful in the next couple of days."
Eaglesmere Lakes is another place to see fall colors for the active types - this great fall hike is about 7 miles round-trip, rated intermediate and appropriate for families and animals on leashes.
Highlights to this hike are the great vistas overlooking Lower Cataract Lake, views of Eagles Nest Peak and The Williams Fork Range that are home to spectacular fall foliage.
According to the Summit County Explorer, the trailhead is 16 miles north from Silverthorne on Highway 9. To reach the trailhead, turn left onto Heeney Road and go about 5.25 miles to County Road 1725. At this juncture turn left and continue for 2 miles until reaching the Eaglesmere Lakes Trailhead. Take the right fork and drive to the nearby parking area.
Though nature puts on a great show this time of year offering several places to see changing leaves, the biology behind the color changes is quite complicated.
To put it simply, trees put on their fall display because of the length of night, temperatures and different leaf pigments that come into play.
According to the U.S. Forest Service, the leaves of certain trees and plants start changing colors as we enter fall because we have shorter days and longer nights. Once this sets in, a biochemical process in each leaf starts changing the leaves colors to the dazzling golds, oranges and reds seen in aspen leaves and other trees and shrubs.
The ideal conditions for the best display of these colors features a temperate climate with warm days and cooler but not freezing nights.
A color palette needs pigments, and there are three types that are involved in autumn color:
"Carotenoids" produce the yellow, orange, and brown colors in hues found in corn, carrots and daffodils.
"Anthocyanin" pigments give color to cranberries, red apples, concord grapes, blueberries, cherries, strawberries and plums.
Carotenoid and anthocyanin pigments are activated when autumn brings longer nights and cooler temperatures.
Chlorophylln gives leaves their green color, but photosynthesis, the chemical reaction that enables plants to use sunlight to manufacture sugars for food, ceases and enters a dormant period during the winter, explains Terry Collins from the Forest Service office in Golden.
"The appearance of fall colors shifts each year due to weather," Collins said. "Heavy cloud cover causes leaves to stay green longer, high evening temperatures cause cells to burn accumulated sugars, so less red and purple pigments are formed and yellow and orange are the predominant colors. Stress from drought and wind cause leaves to drop prematurely."
The ideal conditions are warm, sunny days and cool nights with little wind or drought stress, he added.
For more information visit www.fs.fed.us/fallcolors.