Shorter days mean Colorado's trees are ready to change colors: make plans to escape the city to see them

With autumn arriving, trees are starting to show off their fall colors in Colorado. The primary factor in when the leaves change is the length of our nights.

Pigments in the leaves determine what color appears as the green fades. That happens as chlorophyll production slows and stops as the days grow shorter. When that stops, those other pigments appear. In Colorado's mountains, that means those stretches of golden aspen trees.

Weather in the weeks before chlorophyll production impacts just how brilliant the colors will be. The U.S. Forest Service says it seems a succession of warm, sunny days with crisp, but not freezing, nights create the most spectacular displays.

Colorado truly becomes colorful as the leaves change with popular drives close to the Denver metro area like Guanella Pass, Kenosha Pass and the I-70 corridor west of Denver. But if you want to make a weekend of it or play hooky for a few days during the week, consider heading farther away.

Leaves should already be turning in the Steamboat Springs area. It's a bit more than a three hour drive to the town from Denver. You're on the edge of Medicine Bow-Routt National Forest. In addition to leaf peeping, make sure you take time to check out the hot springs. The Old Town Hot Springs is near city center and has swimming and soaking pools, plus water slides. And a little bit outside of town is the popular Strawberry Park Hot Springs.  

The web site "Trips to Discover" lists Silverton among the best small towns in the country to visit for leaf peeping. The only incorporated municipality in San Juan County is a 6.5 hour drive from Denver but you'll find both aspens and oaks, making for a variety of colors. It's one of the 25 mile stretch of U.S. 550 known as the Million Dollar Drive. In town, you'll find a real taste of the Old West with saloons and hotels plus the Durango & Silverton Narrow Gauge Railroad.

Head southwest of Denver to enjoy the changes in the leaves around Pagosa Springs. The drive of about 5.5 hours takes you down U.S. 285, which offers plenty of lovely views with or without changing leaves. In the town, you'll again find a variety of hot springs including the Mother Spring, the world's deepest geothermal hot springs. And you can check at Wolf Creek Pass along U.S. 160.

Telluride is a popular destination any time of the year, with a drive that takes just more than 6 hours if you choose the I-70 route or almost 7 if you choose to go through Buena Vista and Montrose. The town's web site promises a mix of bright yellows, oranges and reds in a calmer box canyon. Telluride hosts a number of fall festivals including the autumn Classic, Original Thinkers and Horror Show. You can grab a free ride on the gondola to get a bird's eye of the leaves.

But don't discount the Denver metro area for leaf peeping. Keep your eyes open in parks and neighborhoods for rich, changing leaves around any corner.