Canadian ranger Allen Pogotak looks out over the ice during a sovereignty patrol near Eureka, on Ellesmere Island, Nunavut, March 31, 2007. (Jeff McIntosh/Canadian Press)

During a visit to Ellesmere Island in August 2006, Prime Minister Stephen Harper declared: "Sovereignty is not a theoretical concept, you either use it or lose it." In fact, the main purpose of Harper's trip to Nunavut, then the Northwest Territories and the Yukon was to reassert Canada's claim of sovereignty over Arctic waters — and particularly over the Northwest passage, which the U.S. claims is an international waterway.

The high-stakes game of Arctic sovereignty involves military icebreakers and submarines sliding under ice packs, but also Canadians patrolling on snowmobiles in temperatures as cold as –50 C, pushing into winds of up to 115 kilometres an hour.

These were the conditions facing the most recent Canadian Forces "sovereignty patrol," a $1-million exercise that started on March 24 and concluded on April 9.

Like many these patrols, the group was primarily made up of Canadian Rangers, part-time reservists who volunteer to provide a military presence in remote, isolated and coastal communities in Canada.

There are some 4,000 Canadian Rangers in 165 Canadian communities, with plans to expand the force to 4,800 by 2008. Most of the Rangers are Inuit.

The latest patrol was headed by Maj. Chris Bergeron, the commanding officer of the 1st Canadian Ranger Patrol Group, and included 17 red-suited Rangers, seven regular Canadian Forces soldiers and a Mountie.

The members divided into three teams, fanning out across Ellesmere Island. They patrolled a total of 8,000 kilometres from Resolute Bay to Alert, the northernmost permanently inhabited settlement in the world and Cape Aldrich, Canada's most northerly point.

Bergeron said the most difficult part of the expedition was along the west coast of Ellesmere Island, a barren, brutal stretch of white hell last traversed in 1906 by U.S. explorer Robert E. Peary.

Sgt. Peter Moon, a spokesman for the Rangers, told CBC News Online that when Bergeron's patrol reached Cape Aldrich, it located a cairn left by Peary.

The patrol also stopped at Ward Hunt Isle, where Moon said the Rangers erected a metal flag "to remind these people they are leaving Canada."

Rangers started amid fears of Japanese invasion

The Rangers began as the Pacific Coast Militia Rangers (PCMR) on March 1942, at the height of the Second World War. They were volunteer soldiers whose job was military surveillance along the coastlines of British Columbia and in Yukon against the threat of a Japanese invasion.

They once numbered 15,000 volunteers in 138 communities.

The PCMR was officially stood down on Sept. 30, 1945.

The Canadian Rangers took over on May 23, 1947, charged with northern and Arctic surveillance, most often by means of these sovereignty patrols.

They are a volunteer force, paid only when in training and on special missions. Their motto is "Vigilans," often interpreted as "The Watchers."

Canada honoured the Rangers in 2003 in a ceremony in Yellowknife when a commemorative Canada Post stamp was unveiled featuring a red-clad Ranger peering into binoculars at a mountain-capped northern scene.

Moon told CBC News Online that the Rangers still use the old .303-calibre Lee Enfield, a heavy bolt-action rifle designed a century ago but considered extremely accurate and reliable in Arctic temperatures.

The Rangers use them to kill animals for food, as well as carrying 12-gauge shotguns to protect themselves from animal predators.

The patrols are aimed in part at training soldiers to put up camps in extreme conditions, and learning to communicate with the air force from ground to air by radio.

On the latest patrol, they were also asked to be on the lookout for Inuit hunters from Greenland because of reports they were poaching Canadian polar bears in northern Ellesmere Island.

The patrol did not encounter any poachers — and Moon said that was a good thing, because they had to expend too much effort simply to set up camp in the fierce winds.

Moon said the Rangers use snowmobiles to anchor their tents, putting three of the vehicles on the sides of each tent and leaving for an open flap away from the wind.

There was one woman Ranger on the most recent patrol, an Inuk named Liza Ningluk of Grise Fiord, who is in her 50s and a community elder also held in great respect by her fellow soldiers.

She's one of a number of women who have become Rangers. In Ontario, as many as one in three are women. There are also 3,800 Junior Canadian Rangers, who are ages 12 to 18.

There are also a few Rangers in their 80s, because there is no compulsory retirement among the Rangers. They do not go on sovereignty patrols such as the most recent one, but they pass on wisdom and serve a function similar to military chaplains.

Moon said two Inuit Rangers in their 80s, both of whom live in Nunavut's Belcher Islands, signed on when the Rangers were formed in 1947.

Back then, Moon said, they were given red arm bands, rifles and 200 rounds of ammunition each. They have remained Rangers ever since.

There have been many previous sovereignty patrols, including in:

2006: Five teams of Rangers patrolled nearly 5,000 kilometres, starting from Mould Bay in the Northwest Territories and from Isachsen, Grise Fiord and Resolute Bay — all in Nunavut — and ending at Resolute Bay. They gathered information on equipment and airfields that would be helpful in emergencies such as major air disasters.

2005: Operating out of an abandoned weather station at Isachen, a 22-member patrol travelled 1,000 kilometres in two weeks, exploring various Arctic islands and leaving behind cairns.

2004: A 20-member patrol travelled from Resolute Bay to Alert, a trek of 1,754 kilometres, which was the longest sovereignty patrol in Canadian history.

2003: A four-member patrol travelled 750 kilometres in seven days from Eureka in Nunavut to Alert. The patrol came upon areas where snowmobiles could not perform, and was able to pass that valuable information on to the regular Canadian Forces.

2002: A 33-member Rangers patrol travelled 1,700 kilometres from Resolute Bay to the Magnetic North Pole and back in 16 days.