A cyclist had the race of his life Saturday in Yukon as he pedalled to outrun a wolf chasing him along the Alaska Highway.

American Mac Hollan and two friends are cycling to Alaska from Idaho to raise money for charity.

Jordan Achilli, Gabe Dawson and Mac Hollan are bicycling from Idaho to Alaska to raise money for charity. Hollan was chased by a wolf on the highway outside Watson Lake, Yukon, last Saturday. (Facebook)

About 100 kilometres west of Watson Lake, Hollan’s two companions stopped to fix some bike equipment, leaving him to ride ahead. When he heard breathing behind him he thought his teammates had caught up to him.

He looked back to see a wolf pursuing him.

Hollan said his adrenalin kicked in, he changed gears and got far enough ahead of the animal to get his bear spray out.

That's when he blasted the wolf in the face.

"And he backed up about 20 feet and I thought he was going to stop," he said.

"I thought, 'What a wild story. I'm glad that's over.' Then he kept running again and came back up to the back of my bike and actually attacked the back of my bike and ended up ripping the bag that I carry my tent stakes and poles in and ripped it off the back of my bike and spilled it all over the highway."

Hollan said the pursuit continued long enough that four vehicles passed before a couple driving a motorhome stopped to lend assistance.

When Hollan was safely inside the vehicle, the wolf attacked his bicycle that was left on the road.

It only left after another motorist threw a metal water bottle at it, hitting the wolf in the head.

Hollan said he and his friends prepared for bear country, with bear spray, bear bags and keeping a clean camp. They are not going to be deterred from cycling Yukon and Alaska by the incident with the wolf.

"It's kind of hard to worry about it happening again because I think the odds of it happening in the first place were astronomical, and for it to happen twice... I don't foresee that happening."