ANCHORAGE, Alaska (AP) -- The grizzly bear stares at the camera with a look that appears ominous in the last photograph snapped by Richard White just before the animal mauled him to death in Alaska's Denali National Park.

The photo is among 26 snapshots of the male bear taken in an eight-minute time frame by the 49-year-old San Diego backpacker Friday afternoon. National Park Service investigators are scrutinizing the images, hoping to gain a better understanding of the attack as well as confirm estimates based on the photos that the bear was between 40 and 50 yards from White.

"Definitely way too close," chief park ranger Pete Webster said Monday.

The photos have not been released. Park officials are trying to determine if the photos are in the public realm or belong to White's family, which has asked that the photos not be made public. Several media organizations, including The Associated Press and the Anchorage Daily News, are seeking the photos under public records requests.

White's death is the first known fatal bear mauling in the park's nearly century-long history.

Most of the photographs show the bear head-down and grazing alongside the Toklat River gravel bar, seemingly unaware of a human's presence, according to Pete Webster. The last five photos span about 15 seconds, beginning with the bear lifting its head, no longer foraging. The grizzly then looks toward the camera, then moves a couple yards closer.

The mauling probably occurred almost immediately after the last image.

"A bear could cover that distance before a person could react," Webster said.

The same afternoon of the attack, hikers stumbled upon White's backpack, blood and torn clothing bout 150 yards from his remains. A state trooper fatally shot the bear Saturday and a necropsy determined the bear's stomach contained remains and clothing that confirmed it was the animal that killed White.

White's remains were recovered Saturday evening and were sent to the state medical examiner's office in Anchorage.

White had been in the Denali backcountry for three nights under a five-night permit. He indicated on his permit application that he had hiked in Denali before and altogether had 30 years of backpacking experience. Park officials say White had received mandatory bear awareness training that teaches people to stay at least a quarter-mile away from bears, and to slowly back away if they find themselves any closer. The training takes place before permits are issued.

Such bear-country safety measures have worked for years, and there are no plans to implement changes to park policy, officials said.

"This was an avoidable incident," Webster said. "The hiker had opportunity to back away and at least attempt to move around this bear, and it doesn't appear that he did so."

A 150-square-mile section of the park remains closed and no overnight permits for that area are being issued, officials said. With the weather clearing Monday, park pilots were expected to fly over the area to keep an eye out for other backpackers who could wander into the vicinity.

White, who is survived by a wife and young daughter, had been the director of exploratory pharmacology at Ferring Pharmaceuticals in San Diego until last year.

Former colleagues there were shocked and going through "a grieving process," said Paul Acosta, a Ferring human resources executive.

"We are very saddened by the news of the death of Richard White," Acosta said. "He was extremely talented and a kind member of the team."

Denali is located 240 miles north of Anchorage. It spans more than 6 million acres and is home to numerous wild animals, including bears, wolves, caribou and moose.