A Carmacks, Yukon, man was killed when his snowmobile rolled over on him on Saturday near Mandanna Lake, about 50 kilometres southeast of Carmacks and south of the Robert Campbell Highway.

Carmacks RCMP say 37-year-old Jason Wheeler was one of two snowmobilers travelling back to a cabin in the area on two separate machines. 

Police say Wheeler was attempting to climb a hill off the lake when the machine rolled over on top of him. He was pinned under the snowmobile as it slid down the rocky slope.

The second snowmobiler and others at the cabin came to his aid but Wheeler died of his injuries at the scene.

Const. Paul Miller says Wheeler was not wearing a helmet at the time of the crash. Helmets are mandatory for snowmobilers in Yukon. 

"The RCMP would just like to remind the public that if they're out they're on their snowmobiles, they're out there enjoying you know the pastimes that the Yukon does have to offer, that they have to remember to be safe and one of those areas that we need more work obviously is the wearing of the helmet," says Miller. 

An autopsy has not been ordered but toxicology tests are being done to determine if alcohol or drugs played a role in the crash.