Posted by: Steve Shelly, Regional Botanist, US Forest Service Northern Region

Do you think that all evergreen conifers are always evergreen? In general, that’s true but the forested landscapes of the northern Rocky Mountains offer an amazing colorful exception to this each fall with the spectacular shows of the Alpine larch (Larix lyallii).

The Rockies are generally dominated by evergreen conifers – trees that bear cones – so in many areas these landscapes don’t put on quite the displays of color in autumn like those of the eastern forests. Yet, consider this amazing exception. Early each fall, at elevations above 7,000 feet or so in western Montana, the Alpine larch conifer tells its unique deciduous story.

Each October, as the mountain air cools and the first snows dust the top of the peaks, their needles turn a brilliant, yellow-orange color before falling off. In Missoula, Mont., this beautiful coloration can even be seen from the center of town, as one gazes southwest to the Bitterroot Mountains. A brightly colored “cap” can be seen on top of Carlton Ridge, where a large stand of alpine larch puts on a full display – this shining ribbon of trees can be seen from nearly 20 miles away!

These hardy trees live in high, cold places where lots of snow falls each year. In many areas, they are the highest-elevation trees in the Rockies. Every year, these stands are also hit more than once by hurricane-force winds. But still they persist, adding a blast of color to the higher mountains right before the first deep snows come. While you can see the colorful display from a distance, the best way to really appreciate these forests is to hike through them just as their color is peaking. A walk through a changing alpine larch stand is unlike any other this time of year. It’s as if the whole world lights up - even the air itself seems to turn a golden color.