Wyoming’s Famous Grizzly 399 Still Healthy As She Hits Ripe Old Age Of 28

Wyoming’s most famous bear, Grizzly 399, reached a significant milestone this month when she hit age 28, but she’ll have to last at least another six years to match the longest known lifespan of a grizzly in the Northern Rockies region.

Mark Heinz

January 12, 20244 min read

Happy 28th birthday to Wyoming's famous Grizzly 399.
Happy 28th birthday to Wyoming's famous Grizzly 399. (Photo is owned by Jorn Vangoidtsenhoven and may not be reproduced)

Wyoming’s most famous bear, Grizzly 399, reached a significant milestone this month when she hit age 28, but she’ll have to last at least another six years to match the longest known lifespan of a grizzly in the Northern Rockies region, which was 34.

Even so, her chances seem good of living at least long enough to finish raising her huge first-year cub Spirit to maturity, by which time she’ll be pushing 30.

Grizzlies in the wild live an average of 20-25 years.

Grizzly 399 has spent most of her life in Teton National Park, and gained a worldwide fanbase when wildlife photographers began sharing images of her and her various litters of cubs across social media.

Went To Bed On Time

The exact date of 399’s birth isn’t known, wildlife photographer Jorn Vangoidtsenhoven told Cowboy State Daily. But it was likely in January, because that’s when grizzlies are typically born after their mothers have denned for the winter.

Grizzly 399 and Spirit were last seen in November, when they were thought to have gone into hibernation.

Vangoidtsenhoven has photographed 399 for years and posted a “happy birthday” message for her on social media Thursday.

“Grizzlies get born in January typically, but of course no one knows exactly which day she was born — or any wild grizzly for that matter,” he said. “I chose a random date this January to celebrate the event.”

Good Teeth Are The Key

Grizzlies in the wild have rough lives. Many cubs don’t even live long enough to separate from their mothers, which usually happens at around age 2.

For those that live long enough to reach elder bear status, it’s usually tooth decay that does them in. Without good teeth to tear into tougher food such as big game carcasses, older bears frequently starve, or they can’t pack on enough fat to survive winter.

Observers say that 399’s teeth have remained in fairly good shape for a bear her age.

She and her cub appeared to be adequately fattened up before they denned, Vangoidtsenhoven said.

“She's turning 28 and, based on the last sightings in the fall, looked very good going into hibernation,” he said. “Of course, her teeth are showing her age, but based on her appearance and weight, she looked set for a successful winter. Spirit also looked great, so fingers crossed that both will appear at Pilgrim Creek sometime mid-April.”

Lead Bear Biologist Says She’s Looking Good

Despite 399’s advanced age, chances are good she’ll live long enough to finish raising Spirit, bear expert Frank van Manen told Cowboy State Daily.

A momma griz of her vintage is rare, but not unheard of, said van Manen, who is the supervisory research wildlife biologists for the U.S. Geological Survey’s Interagency Grizzly Bear Study Team.

“Based on photos and videos and given her age, 399's condition remains good, so the odds of her raising her cub to independent age are still pretty good,” he said. “She is certainly a unique bear in that regard; however, I would not be surprised if there have been other bears of similar age elsewhere in the ecosystem that successfully reproduced and raised cubs.

“The oldest bear that we have documented was 34 years, a male.”

Adoring Crowds Must Be Respectful

Wyoming Game and Fish Department large carnivore specialist Dan Thompson agreed that 399’s chances are good to survive at least a couple more years. Wisdom gained from experience has served her well.

And having only one cub — as opposed to her 2020 litter of quadruplets — helps too, Thompson told Cowboy State Daily.

“I think her chances are as good as any other adult females in similar circumstances, there is senescence that occurs with all species, humans included, but the fact she is not caring for multiple mouths is a benefit,” he said. “Any long-lived species has the advantage of knowing little ‘secrets’ within the area they live as to food sources and behavioral adaptations they can adopt should something anomalistic occur in any given year.”

Grizzly 399 took her time emerging from hibernation last spring, causing some to fear that she might have perished. But her fanbase erupted with joy when she and her new cub were finally spotted on May 16.

The anticipation this spring could generate similar hype, Thompson said, but adoring throngs should give the bears adequate space.

“People will be waiting in force to see what happens this spring, maybe not yet, but sentries will be posted in the upcoming months and the crowds will gather. We just want people to be respectful of wildlife,” he said.

Mark Heinz can be reached at mark@cowboystatedaily.com.

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Mark Heinz

Outdoors Reporter