Early into the winter season, Colorado avalanche officials have bestowed a “dubious distinction” upon the Tenmile Range and the surrounding Summit County area.

The Colorado Avalanche Information Center warned in a Facebook post Wednesday, Nov. 6, that the first persistent slab avalanche problem of the season has developed in the Tenmile Range and Summit County. Avalanche danger is currently at moderate throughout most of Colorado.

“We are now seeing problems from the October snow that sat on the ground and faceted,” Colorado avalanche officials wrote in the post. “Numerous field reports show a pattern of freshly formed slabs breaking near the ground. If you find a wind-stiffened slab perched on weak snow near the ground, you can now trigger a large avalanche.”

A persistent slab forms when a persistent weak layer is buried by additional layers of snow, according to the Colorado Avalanche Information Center. Persistent slab avalanches can be difficult to predict because they can occur days, weeks or months after the initial avalanche cycle.

In Colorado’s northern and central mountains, slopes where wind has drifted snow are the most tempting places to ride but also the most dangerous. Avalanche officials wrote that these dangerous spots can lure unwary backcountry travelers in “like the song of a Siren.”

To manage risk in these areas, Colorado avalanche officials recommend carefully evaluating snow and terrain to avoid steep slopes with firm hollow snow. Backcountry travelers should also heed the warning signs of cracking and collapsing and divert to lower-angled or wind-sheltered slopes for safer travel.