The Canadian Ski Marathon is the longest and oldest Nordic ski tour in North America. Over two days, participants ski along the 160 kilometer trail that connects Gatineau and Lachute, Quebec. The route passes through mostly private land, and is thus only publicly accessible and groomed once a year, for the event. In 2016, the Canadian Ski Marathon is celebrating its 50th anniversary.

Pick up the January/February issue of Canadian Geographic for the full story.

Skiers in the Coureur des Bois category huddle around fires for warmth at the Canadian Ski Marathon Gold Camp. (Photo: Jessica Finn/Canadian Geographic)

Cross-country skis are just barely visible through the frost- and dirt-covered windows of a school bus transporting skiers to the start of the race in Lachute, Que. (Photo: Jessica Finn/Canadian Geographic)

The marathon attracts participants young and old, and is often a family affair. It's not uncommon for several generations to participate within a given year. (Photo: Jessica Finn/Canadian Geographic)

Cross-country ski participants are given many opportunities to wax their skis as needed along the way. (Photo: JESSICA FINN/ Can Geo Staff)

Canadian Ski Marathon_JB0896.TIF - Participants of the 49th Annual Canadian Ski Marathon limber up at the Start line in Lachute, Que. on Day 1. (Photo: JESSICA FINN/ Can Geo Staff)

The skiers often traverse roads and private properties made available only once a year, for Canadian Ski Marathon participants and support crews. (Photo: Jessica Finn/Canadian Geographic)

Volunteers build and maintain snow bridges, and direct vehicular and ski traffic over them, at road crossings throughout the marathon course. (Photo: Jessica Finn/Canadian Geographic)

Refreshments and snacks are handed out by volunteers to marathon participants at regular intervals along the route. (Photo: Jessica Finn/Canadian Geographic)

Other members of the community also pitch in. Members of a local cub scouts group move bales of hay at the Gold Camp as they anticipate the arrival of skiers in the Coureur des Bois category. (Photo: JESSICA FINN/ Can Geo Staff)

Only members of the gold coureur des bois category may overnight in the course's Gold Camp, which requires that they carry their gear along the entire 160-km course. (Photo: Jessica Finn/Canadian Geographic)

With only their headlamps visible in the early morning hours, marathon volunteers look on as the coureurs des bois stream out of camp back onto the course at 5:30 a.m. (Photo: Jessica Finn/Canadian Geographic)

A skier watches as a volunteer gathers and burns the abandoned hay bales at the Gold Camp. His ski boot is was damaged, forcing him to withdraw from the race. (Photo: Jessica Finn/Canadian Geographic)

Canadian Ski Marathon_JB1949.TIF - Occasionally, a skier with a permanent bib is spotted on the course. Only 355 skiers have ever achieved permanent bib status, requiring participation in the bronze and silver categories, and successful completion of five marathons at the gold level (a commitment of 1,120-km on the course over a seven year period). (Photo: Jessica Finn/Canadian Geographic)