'I could hear bones crunching': Hungry grizzly bear mauls bow hunter

It bit his thigh and left him with a 41-centimetre cut in his head.
It bit his thigh and left him with a 41-centimetre cut in his head. Photo credit: AAP

A US bow hunter has survived being mauled by a grizzly bear in a horrific attack in the US.

Tom Sommer was in the Gravelly Range forests of southwest Montana on Monday (local time) when he and his hunting partner startled a hungry bear feeding on an elk carcass.

The bear charged them, covering the distance in seconds.

Mr Sommer's hunting partner used his bear repellent spray - but it failed to stop the beast. Mr Sommer tried to get his out, but he couldn't release the safety in time.

The bear then savaged him.

"It bit my thigh, ran his claws through my wrist and proceeded to attack my head," Mr Sommer said.

"I could hear bones crunching, just like you read about."

He desperately tried to shoot the bear with his pistol when the grizzly smacked his weapon away.

Fortunately, his hunting partner was able to use the rest of his bear spray, ending the 25-second attack.

"Just like that it stopped," Mr Sommer said.

"He stopped biting me, he got up and started to run away."

Mr Sommer was treated at hospital for his injures, including a 41-centimetre cut in his head that required 90 stitches. However he bears the bear no ill-will.

"Through it all I was very conscious, very level-headed and low key about it," Mr Sommer said.

"Besides some scars, it doesn't appear that I will have any problems.

"I've been a hunter my whole life. I have no grievance against the bear. He was just doing what bears do.

"But I would have shot him just the same."