Mike Glidden's press release was amateurish and lacked for fancy letterhead, but it had a killer pitch: "I did not know the bear was there…" After that, the Anchorage hiker went on to outline what he said was a chance encounter with an invisible bear and explain how lucky he was to escape the meeting unharmed.

Attached to Glidden's emailed pitch were 13 photographs taken in and around Byron Glacier in the Portage Valley recreation area about 50 miles southeast of Anchorage, Alaska's largest city.

One of the photos showed the inside of an oft-visited Byron Glacier ice cave and more. In the right-hand corner of one of three identical cave photos was what appeared to be a bear hide draped over a rock. In the second photo of the set, Glidden had superimposed a circle around that object and labeled it "sleeping black bear."

"I will not say exactly where because I don't what the bear disturbed," Glidden wrote. "It was about 100 miles south of Anchorage (on the Kenai Peninsula) December, 13 2014. I followed a river into a valley and there I found some ice caves....I pointed the camera and snapped into the dark. I never did see what was in there.... I realized when I took the picture, my flash had caught a hibernating black bear only yards from where I was. I had not intended to do so but I went into the lair of a hibernating bear and took a picture of it while it slept."

No one had ever before sent a photo of a black bear hibernating in a glacial ice cave to the media anywhere. There is, in fact, no documented record of a black bear -- or a bear of any sort -- hibernating in a glacial ice cave anywhere. And a study done on denning black bears on the Kenai Peninsula in the 1980s found all of them denning in holes dug in the ground.

In science, theres room for the impossible

Alaska Dispatch News never ran the Glidden story, but it did appear on Anchorage's KTUU-TV Channel 2 on Dec. 16.

No other Alaska news outlets picked up the story. But the Alaska office of the U.S. Bureau of Land Management did link to it on the agency's Facebook page and warn people to stay out of ice caves so as not to wake hibernating animals, though there are no records of any animals ever hibernating in glacial ice caves. That was it as far as local attention.

The relative lack of interest in Alaska did not, however, stop the story from going national and global. Glenn Beck's website, The Blaze, was the first to jump on it. The Weather Channel was quick to follow, and the story made enough of an impact elsewhere that when I called Glidden to ask him a few questions about the story one of his first comments was this:

"Are you trying to debunk the story that has gone viral?"

One follow-up question came quickly to mind: Was there something in need of debunking?

More than a week after Glidden's story made the national news, biologist Sterling Miller, the dean of Alaska bear researchers, would make the observation that Glidden's bear, "if it is a bear, is almost certainly dead and not denning. Denning bears are very easily awakened, and this bear would have been wide awake with that dog and person there."

Yet in the immediate aftermath of the story, the scientists all played cautious. Scientists like to whine a lot about the abysmal quality of science reporting in the media today, but when it comes time to help fix the problem they seldom want to put their necks on the line because in the world of science the impossible happens now and then.

With the media reporting a bear hibernating in an ice cave, no one I spoke to wanted to publicly label the claim untrue because it could happen, because animals -- like people -- engage in all sorts of strange and out-of-the ordinary behavior.

Any scientists asked about Glidden's bear story before it appeared in the media would have warned a reporter not to go there without real evidence. But after the fact, things changed.

After the fact, it's hard to prove a negative. From KTUU to The Weather Channel, whether the media meant to or not, they gave Glidden's claim the imprimatur of credibility. No scientist wanted to gamble a career on stating the obvious because there was a chance -- one in a million or less, but a chance nonetheless -- there was a bear or bear carcass in that ice cave.

The most-visited ice cave in Alaska

I had the same reaction to Glidden's bear story that the bear biologists had. But I decided to visit the cave nonetheless.

First, though, I called Glidden to ask him some questions. I admitted to him that to me, the object in his photo didn't look like at all like a hibernating bear, and the incident he described was like no encounter with a hibernating bear on record.

The animals don't sleep all that soundly. His yelling in the ice cave would almost certainly wake a hibernating bear, and his dog getting within a few feet would clearly wake a hibernating bear. A bear's nose never sleeps. A dog smells like a wolf, and letting a wolf -- possibly the leader of a whole pack of wolves -- get within feet when you are a sleeping bear is a precursor to being bear dinner for wolves.

All of this is well documented. Timothy Laske, a scientist with Medtronic, implanted heart rate monitors in some black bears for a year, followed them through hibernation, and discovered that even when hibernating, the animals remain very alert to any activity outside their den, let alone in it.

Biologist Lynn Rogers in Minnesota put a camera in a den of a hibernating black bear. The camera revealed that hibernating bears often don't sleep at all. They're regularly awake during hibernation.

I told Glidden it was beyond belief that he'd encountered a hibernating bear. The Byron Glacier cave is the most accessible such cave in the state, and people have been tramping around it for more than 40 years. In all that time, no one has ever reported seeing a bear of any sort. The cave didn't seem to be the sort of place into which a bear would normally venture, let alone hibernate. But there was a possibility there was a bear carcass in the ice cave. A bear might have staggered in there, slumped over a boulder and died, which -- if you bought Glidden's belief that his photo was of a bear -- was what the photo looked like.

I asked Glidden to go back to visit the scene. He said he didn't want to wake the bear. I told him we'd be quiet and careful. A plan was made to meet at Alaska Dispatch News' Anchorage office at 9 a.m. on a Friday to drive down the Seward Highway to the cave. Glidden never showed. Four calls to his cell phone went unanswered.

At about 10:30 a.m., I headed for Byron Glacier. I picked up my Labrador retriever, Lars, on the way. He barks to warn of bears. He's done it many times. I figured it was a good idea to have him along to try to find the bear.

Do not do this

In Portage, the temperature was 38 degrees. It was raining. Lars and I pushed on anyway. There were some old human tracks in the skim of old snow left on the Byron Glacier Trail, but no bear tracks.

Up valley near the entrance to the cave, there were even more human tracks. Again, no bear tracks. We went into the cave and its various passages and poked around for an hour or so. It was as long as I could tolerate. There was a legitimate worry about falling ice.

The cave Glidden had described on his Facebook page -- a dark cavern off a 65-yard tunnel beneath the glacier -- was easy enough to find. There is no other cavern like this in the valley.

But the cave held no bear. There was no sign any bear had ever been there. Lars faithfully sniffed around. He gave no indication he smelled anything. I took some photographs. They raised more questions about Glidden's story.

After I left the ice cave, I called Glidden again. He didn't answer. I left the message that there was no bear and asked him to call back. He never called.

Two days later, I used another phone -- one lacking my caller ID -- to reach him. Why, I asked, would anyone make up a story about a bear hibernating in an ice cave?

"I don't know," Glidden said. "You can make your own decision, sir. I'm glad you enjoyed your outing, and don't call me again."

Then he hung up.

What Glidden thinks is hard to know. Maybe he really believes there was a hibernating bear in the cave, and it got up and left after he was there, though the bear would need to levitate out of the cave to get away without leaving tracks.

Glidden was there on Dec. 13. I was there on Dec. 19. There was considerable rain in the Portage area over the course of those six days, but no new snow. The tracks around the entrance to the cave were left over from days earlier. They might well have been Glidden's tracks.

There was no ice-cave hibernating bear -- just as there have been no ice-cave hibernating bears before.