A sow grizzly attacked and killed a 28-year-old Whitehorse man who came within five metres of her and her cubs inside their den Friday while staking a mineral claim east of Ross River.

Jean-Francois Page was pronounced dead at the scene by two investigating RCMP officers and a conservation officer with the Department of Environment.

Ross River RCMP Const. Brian White said today police were notified by members of the staking crew at about 4:30 p.m. that one of their co-workers was missing, as they were unable to raise Page by radio.

A search by helicopter, using GPS co-ordinates provided by the crew, located the line Page was flagging about 30 kilometres east of Ross River and subsequently the site where the body was located, he said.

White said while the helicopter was over the scene, the bear exited the nearby den and was shot and killed for safety reasons.

The crew landed some 600 metres away at the nearest available landing site and hiked the uneven terrain to the location, he explained.

The name of the company Page was working for is not being released at this time. The man, originally from Quebec, had lived in Whitehorse for several years.

White said Page would not have been able to see the den site, as it was located above the area he was walking in.

Environment spokesman Dennis Senger said today it was determined the two cubs were not yearlings but rather young of the year, born in February, and officials with the department returned to the den site Saturday and shot them.

'After discussions with the conservation officers and supervisors, it was determined the cubs were too young and they would not have survived on their own,' he said.

Senger said killing the cubs was the most humane approach, as opposed to having them starve to death over time.

It is standard policy to search for and kill bears that have mauled or killed an individual, he said.

Bear biologist Ramona Maraj said the necropsy she conducted on the bear Saturday night after it was transported to Whitehorse indicated the sow was at least 25 years old, of average size and in good health.

Its not uncommon for grizzlies to live into their mid-30s, she said.

Maraj said grizzly cubs normally spend two winters inside the den with the sow, first as young of the year and then as yearlings.

Male grizzlies are generally the first to emerge from their dens sometime around mid-April, followed by lone females from mid-April to mid-May and by sows with cubs from early May to late May.

Page's death occurred on the same day an estimated 250 people gathered in the Yukon government's main administration building to remember those killed on the job.