Imagine travelling to beautiful Colorado and blazing a new hiking trail that will become part of the world’s outdoor history forever. Surprisingly, almost any traveller can have this experience free of charge.

Volunteers with the Continental Divide Trail Alliance (CDTA), a non-profit organization based in Golden, Colorado, can build completely new sections of the Continental Divide Trail (CDT), a 3,100-mile hiking trail that stretches from Mexico to Canada, across Colorado, New Mexico, Wyoming, Montana and Idaho.

“If you’ve never done it before, it’s a real eye-opener,” said Anneliese Ring, an outdoor enthusiast who has volunteered on the CDT multiple times. “When you go hiking, you never think about how these trails come about. But once you get involved with trail work, you realize just how much goes into it.”

Volunteers dig out the trail, clear vegetation and move huge boulders and trees from the established route. In Colorado, they sometimes work in avalanche zones and at altitudes as high as 13,000ft. (Videos show volunteers hard at work in Colorado and New Mexico.)

“It’s very physical, but it’s also very rewarding,” Ring described. “You meet like-minded people that love the outdoors and don’t mind putting in the hard work [to make the outdoors accessible to others].”

Volunteer trips can last from one day to one week, and visitors can participate in more than one project over the course of the volunteer season, which runs from April to October. Projects for 2012 will be announced in February. In addition to trail building, volunteer activities include maintaining the existing trail (often in national parks), helping the crew chefs prepare meals at base camp and participating in educational outreach.

“Not a lot of people know about this opportunity,” said Stephanie Friday, the volunteer programs manager for the CDTA. “Having new trail construction projects is pretty unique to America right now because most of the [country’s hiking] trails are finished.”

Since the CDT is a young, yet-to-be-completed trail, it is not nearly as well known among international travellers as the eastern United States’ Appalachian Trail, Friday said. “But a lot of our thru-hikers do actually come over from Europe. So they’re hearing about it somehow,” she added.

At work sites with high elevations, like the beautifully scenic site near Winfield, Colorado, trips are limited to three days and 20 to 30 volunteers build 600ft of new trail. Although the work can be strenuous, no previous experience is necessary. Volunteers only need to fill out a health evaluation form before being able to work.

Trip leaders provide all gear, food and water, but volunteers should bring tents, sleeping bags and a day pack for camping near the project site. The CDTA also recommends taking precautions against altitude sickness. If flying into the area, stay at a lower elevation for a couple of days before heading up to the site.

After hours of hard work on the trail, the volunteers are rewarded with more than just a nourishing meal. “The wonderful thing is that at the end of the day, when you all sit down and eat together, you share what happened that day,” Ring recounted. “And it develops great camaraderie.”