Snowpack

hiker in sun-cupped snow
See gallery of snow pictures, below.

One of the most frequent questions we get from Trail users each spring is “When is The Colorado Trail likely to be snow free?” The general rule is that most of the CT is snow free by early July and, except for an occasional dusting at higher elevations and on some north-facing hillsides where the Trail is shaded in the trees, it will likely stay that way into September. This can vary by a couple of weeks either way depending on the harshness of the previous winter.

To be safe, we suggest July 1 as the earliest start date for most hikers, bikers and horse riders who plan to go long distances on the Trail. Those who start from Denver in the “iffy” month of June can expect to encounter snow, sometimes several feet deep, as early as the approach to Georgia Pass in Segment 6 and along the Ten Mile Range in Segment 7. Those leaving from Durango can expect to encounter it even earlier in their treks into the San Juan Mountains.

Following the Trail when it is buried in snow is challenging even with the aid of GPS. And unless you are willing to add the weight of snowshoes or skis to your load, you can expect to do a lot of “post-holing,” plunging with each step up to your knees or hips in snow. Post-holing is exhausting, excruciatingly slow and dangerous – an invitation to sprains, strains and ACL tears. Few people who have experienced it are game for more. This video shows what it can be like.

Check our website for the latest information on snow depth as your trip approaches and be prepared to make adjustments accordingly. Information from Trail users posted on social media sites can also be helpful.

Another resource is SNOTEL (short for snow telemetry), an automated system of snowpack and related climate sensors operated by the Natural Resources Conservation Service of the U.S. Department of Agriculture. But beware of its limitations. A longtime CTF volunteer who has monitored SNOTEL weather stations for years points out that virtually all of the SNOTEL sites near the Trail show zero inches of snowpack by the first week of June, even though there may still a lot of snow on the Trail at treeline and above. This is likely due to the location of most of the SNOTEL stations.

There are, however, two particularly helpful SNOTEL sites at Fremont and Red Mountain passes, which are more representative of the higher elevation areas on the CT. Fremont Pass is centrally located on the CT north of U.S. Highway 50 and Red Mountain Pass is centrally located on the CT south of Highway 50.

The rules of thumb:

  • About one week after the Fremont Pass SNOTEL registers zero inches of snowpack, the high points along the north half of the CT (including in Segments 6, 7 and 8) become passable. Around three weeks after the zero snowpack reading, the high points along the Collegiate West (including CW02-CW05) become passable.
  • About two weeks after the Red Mountain Pass SNOTEL registers zero inches of snowpack, the high points along the south half of the CT (including Segments 21-27) become passable.

These SNOTEL links show current snow depth at 11 mountain locations (including Fremont and Red Mountain passes) that are relatively near the CT and at similar elevations.

Snowtels relevant to the Colorado Trail

Nearest CT Location Snotel Site Site Elevation Approx. miles from CT Snow Depth Last 7 Days
Segment 6
Georgia Pass
Michigan Creek 10,600 1.5 Snow Depth Michigan Creek
Segment 8
Copper Mountain
Copper Mountain 10,300 0.3 Snow Depth Copper Mountain
Segment 8
Kokomo Pass
Fremont Pass 11,400 3.7 Snow Depth Fremont Pass
Segment 15
Fooses Crk/ Marshall
Porphyry Creek 10,760 3.3 Snow Depth Porphyry Creek
Segment 17
Sargents Mesa
Sargents Mesa 11,530 0.3 Snow Depth Sargents Mesa
Segment 18
Cochetopa Pass
Cochetopa Pass 10,020 0.8 Snow Depth Cochetopa Pass
Segment 22
Jarosa Mesa
Slumgullion 11,440 3.5 Snow Depth Slumgullion
Continental Divide atop Elk Creek Beartown 11,600 0.6 Snow Depth Beartown
Segment 24/25
Molas Pass
Molas Lake 10,500 0.3 Snow Depth Molas Lake
Segment 25
Rolling Pass
Red Mountain Pass 11,200 9.3 Snow Depth Red Mountain Pass
Segment 27/28
Kennebec Pass
Columbus Basin 10,785 0.9 Snow Depth Columbus Basin

Gallery of snow