A grizzly sow that had come to view humans as a source of food in Glacier National Park has been killed by rangers, who also accidentally killed one of her yearling cubs when they tried to tranquilize it. The killings Monday brought to a close a long-running effort by park rangers to get the sow and her two cubs to rely on their natural food sources and to avoid backcountry travelers.

The 17-year-old sow, nick-named the "Oldman Lake Bear," was shot by two rangers armed with rifles as she and her cubs were heading towards the backcountry campsite at Oldman Lake in the park's southeastern corner, not far from Two Medicine Lake. The two yearlings were darted with tranquilizers about an hour later, and one died from the drug despite mouth-to-nose CPR efforts by the rangers. A necropsy -- an autopsy -- will be conducted to try to determine why the cub died. Possible causes include the tranquilizer dart hitting a vital organ, an improper dosage, or shock.

"The unintended death of this yearling grizzly is a very unfortunate outcome of a very difficult operation," Glacier Superintendent Chas Cartwright said Tuesday in a prepared statement. "The National Park Service will conduct a thorough review of the cause of death of the yearling, but we are also relieved to have captured the other yearling."

The killings came in a popular and incredibly scenic part of Glacier. The thickly forested area is hard along the eastern flanks of the Continental Divide, dotted with lakes and spread out below glacially horned peaks. There are a number of designated backcountry campgrounds in the area, which also is very popular with day-hikers. Last summer the area saw roughly 3,200 backcountry camper nights, while over the past decade the average has been right around 3,000, according to park officials.

Glacier officials realize the killings will likely bring condemnation from some corners, but believe they had no other choice.

"There are numerous bears in the area that don't walk through the middle of campgrounds with their cubs," Jack Potter, the park's chief of science and resource management, said Tuesday. "We did not feel safe with having that bear out there. ... We knew it was going to be unpopular. It's been very hard on our staff. Nobody likes to do this. Nobody joins the Park Service to kill animals. ... If someone had gotten mauled, it (criticism) would have been the other way."

Glacier has a grizzly population of about 365 animals, according to a U.S. Geological Survey census in 2004. While bears are common in the area where the sow was killed, areas with greater grizzly densities can be found elsewhere in the park.

The last time the Park Service put down a Glacier grizzly was in 1998, when rangers tracked and killed one believed to have killed and devoured a backpacker near Scenic Point east of Two Medicine Lake. The decision to kill the sow this week was made only after years of efforts to dissuade her from viewing backcountry campgrounds as buffets.

“Unfortunately, this entire family group of grizzly bears had become overly familiar with humans," Superintendent Cartwright said. “Park resource personnel worked to keep this bear and her offspring in the wild for five years, but given her most recent display of over-familiarity in combination with her history of habituation, we determined that the three grizzlies posed an unacceptable threat to human health and safety; and therefore, needed to be removed from the park.”

In 2005 and again in 2006 this section of backcountry was closed because of the sow's behavior, said Chief Potter. Additionally, Karleian Bear Dogs were brought in for about two weeks both summers with hopes they could convince the sow and her offspring to avoid humans, he said.

While the sow seemed to vanish in 2007 and 2008, this year she was "back doing the same things," said the chief. "I hate to assign personifications with these animals, but she was boldly going after these camps."

The bears had been closely monitored in recent weeks. Rangers were actually stationed in some of the campgrounds to observe their behavior, and twice they were approached by the bears. The sow's demise came Monday about 4:30 p.m. when rangers spotted her and her yearlings about 300 yards from the Oldman Lake backcountry campground and heading toward the site. Rangers were about to close the backcountry campground, which was occupied, when they spotted the bears.

After the female was killed, rangers arranged for helicopter support and to retrieve drugs to dart and tranquilize the two yearlings that remained in the vicinity. The yearlings were darted over an hour later. One cub died shortly after being tranquilized despite efforts by rangers to resuscitate the yearling by performing mouth-to-nose CPR.

Glacier’s internationally-vetted Bear Management Plan and Guidelines specifies that conditioned bears that display over familiarity must be removed from the wild population. While park officials reached out to find a facility that might take the sow and cubs, no zoos or other federally-authorized captive facilities were willing to take an adult bear. The Bronx Zoo in New York City was willing to take the yearlings. Now just one will be shipped there.

Glacier's bear management policy is to maintain natural population dynamics and, to the extent possible, promote natural behavior in the presence of humans. So far in 2009, three separate incidents had been documented in which the female grizzly exhibited behavior that could be classified as “repeatedly and purposefully approaches humans in a non-defensive situation.” The female was again demonstrating this same behavior on Monday afternoon when she was shot and killed approaching Oldman Lake campground.

“Given the possibility that her offspring had learned this type of overly-familiar behavior and the diminished chance of their survival, we simply could not leave the yearlings in the wild. We deeply regret the loss of the one cub, but are thankful that the other yearling will soon be transported to the Bronx Zoo,” Superintendent Cartwright said.

The female had frequented the Morning Star and Old Man Lake backcountry campgrounds, both in the Two Medicine/Cut Bank area repeatedly since 2004. During that time, the sow produced two sets of offspring. Throughout this time, both the sow and her offspring approached hikers, forced hikers off trails, came into cooking areas while people yelled and waved their arms at the bears, and sniffed at tents during the night. Numerous efforts were attempted to haze the female and her offspring away from backcountry campsites.

“As a protected species under the Endangered Species Act, the decision to remove the family of grizzlies was not taken lightly, but was the result of Glacier’s ongoing coordination with the U.S.
Fish & Wildlife Service, the agency charged with administering the Endangered Species Act," said Superintendent Cartwright.