A grizzly bear roams near Beaver Lake in Yellowstone National Park, Wyoming, July 6, 2011.

A man calling 911 from Yellowstone National Park can be heard telling  rangers that he believes a grizzly bear is attacking a hiker and he can hear the man screaming for help.

Authorities released the 911 calls today from grizzly attack that left a man dead in July.

The calls show a concerned hiker from a party of six that can hear the frantic screams of a man and a woman near Wapiti Lake.  The attack eventually claimed the life of 57-year-old Brian Matayoshi, who was hiking with his wife Marilyn.

The first call that came in to 911 dispatchers wasn’t sure what happened.

“A couple may have possibly been attacked by bears,” the caller says. “Should we try to go in and get the person out?”

He tells the 911 operator that his party had just seen a mother bear and baby cubs go by, and then heard a man and a woman yelling from father up the trail.

“It sounded like they were trying to scare the bear. I hear a man’s voice making loud animal noises, trying to scare it,” the caller said. “I heard a woman,  it sounded like she was scared.”

The operator tells the man that rangers will look into it, but a short time later, the same hiker calls back.

“We can hear someone calling for help,” he said. “All I can hear is a lady’s voice. There was a man as well. We’re worried that the man may be injured.”

The caller then identifies himself as a trauma surgeon and offers to go into the trail toward the yelling if the operator and rangers think it is a safe move. They advise him not to go.

The man was pronounced dead at the scene, while the woman suffered only minor injuries.