Early October in the Colorado mountains is a true in-between season: gold aspen stands linger in the valleys while the high peaks wake up with the first sugar-dustings of snow. Mornings start frosty and glass-calm on Dillon Reservoir; by afternoon you’ll often peel off a layer under bright, 60-something sun—until a surprise squall reminds you winter is close. Elk are still bugling at dawn, trails are quieter, and the last pockets of color glow along Blue River, Frisco and Dillon. Breckenridge, Keystone, Copper, and A-Basin test snow guns on crisp nights, towns swap summer patios for pumpkins and cider, and locals squeeze in one more bike ride or hike before the clocks change and skis come out for good.