![\"In](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/10\/carcass-man-2-10-10-25.jpg\")
In this photo from March 1986, Biologist Dave Mattson of the documents a winter-killed elk carcass on an island in the Little Firehole River in Yellowstone National Park. (Courtesy: Jeff Henry)March 25 Was The Pivotal Date<\/p>\nOver the course of 47 winters in Yellowstone National Park, Jeff Henry has seen incredible\u00a0changes. He can\u00a0recall back when so many winter-killed bison and elk carcasses littered the basins near Old Faithful, counting them was a full-time job.\u00a0<\/p>\n
Nowadays, wolves and grizzlies gobble the carcasses up quickly, there\u2019s really no point in counting them, Henry told Cowboy State Daily.<\/p>\n
He still works seasonally in Yellowstone, and is preparing for his 48th\u00a0winter there.<\/p>\n
One of his main tasks is clearing\u00a0snow off roofs, \u201cso the buildings don\u2019t collapse from the weight,\u201d said Henry, who lives in the Paradise Valley area of Montana.\u00a0<\/p>\n
He worked in Yellowstone way back when \u201cGrizzly number 1\u201d was wandering the countryside. And he was once chased and nearly caught by Grizzly 83, a female.\u00a0<\/p>\n
Now, the number designations assigned to bears by researchers have topped 1,000.\u00a0<\/p>\n
For instance, one of Grand Teton National Park\u2019s favorite bears is designated Grizzly 1063.<\/p>\n
Counting Carcasses\u00a0<\/p>\n
Henry\u2019s first job in Yellowstone was working concessions in 1977. Before long, he met members of the U.S. Geological\u00a0Survey\u2019s\u00a0Interagency Grizzly Bear Study Team (IGBST).\u00a0<\/p>\n
Since the 1970s, the team has been tasked with monitoring and studying grizzlies throughout the Greater Yellowstone Ecosystem.\u00a0<\/p>\n
From the beginning, whenever a grizzly is captured, tranquilized and studied, it\u2019s given a number designation,\u00a0which becomes their defacto name to both the scientific community and the general public.\u00a0<\/p>\n
Hence, well-known bears like Grizzly 610, and the most famous of them all, the late Grizzly 399.\u00a0<\/p>\n
A vital part of bear research was documenting and counting winter-killed bison and elk carcasses in places such as the Firehole Basin.\u00a0<\/p>\n
That tied into the IGBST\u2019s work, because the carcasses were vital food source for grizzlies when they emerged from their hibernation dens in the spring.<\/p>\n
Henry started helping biologist Dave Mattson and other team members with counting and documenting carcasses.\u00a0<\/p>\n
By the early 1980s, it had become his full-time job.\u00a0<\/p>\n
At the time, several thousand elk and bison wintered in the geyser basins around Old Faithful.\u00a0<\/p>\n
Winter inevitably took its toll. Animals would die from exposure, starvation or old age.\u00a0<\/p>\n
The grim count varied year-to-year, Henry said.\u00a0<\/p>\n
After a \u201cpuny\u201d winter, in spring 1987, he counted 17 carcasses.\u00a0<\/p>\n
The winter of 1988-1989 was a different story.<\/p>\n
During the summer of 1988, gargantuan wildfires burned roughly a third of\u00a0Yellowstone. Much of the forage that bison and elk depended on was consumed by the flames.\u00a0<\/p>\n
So, the animals were already short on\u00a0food and fat reserves,\u00a0going into that winter. And it turned out to be a brutal one.<\/p>\n
In spring 1989, Henry counted 489 carcasses, the most ever during his watch.\u00a0<\/p>\n
His last year of counting carcasses was 1992. He went on to hold other positions in the park,\u00a0including park ranger.\u00a0<\/p>\n
In this photo from March 1986, Biologist Dave Mattson of the documents a winter-killed elk carcass on an island in the Little Firehole River in Yellowstone National Park. (Courtesy: Jeff Henry)March 25 Was The Pivotal Date<\/p>\n
When Henry started working in Yellowstone, there weren\u2019t any wolves there. Wolves had been eradicated decades before.\u00a0<\/p>\n
And there were far fewer grizzlies.\u00a0<\/p>\n
Nature\u2019s carcass disposal crews mostly consisted of smaller critters, such as coyotes and ravens.<\/p>\n
Back then, a full-sized bison carcass might last for nearly a month before it was fully consumed.\u00a0<\/p>\n
The few bears that there were did their part.\u00a0<\/p>\n
Henry noticed a pattern in their feeding schedule.\u00a0<\/p>\n
\u201cI would find the first grizzly tracks of the season within a day of March 25 each spring,\u201d he said.<\/p>\n
It turned out that the typical date of death for the elk and bison which perished was also March 25.\u00a0<\/p>\n
So, it seemed that the grizzlies knew to wake up and emerge from their dens right when a \u201cmeat bonanza\u201d was available for breakfast.\u00a0<\/p>\n
He noticed similar\u00a0patterns with other food sources. Grizzlies\u00a0seemed to show up right when certain berry patches ripened, or when trout spawning runs began on the outskirts of Yellowstone Lake.<\/p>\n
\u201cBears have an incredible map of their home range in their minds. And they also have a calendar (of food sources) in their minds,\u201d he said.<\/p>\n
![\"The](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/10\/fire-1-10-10-25.jpg\")
The massive wildfires in the summer of 1988 changed Yellowstone National Park forever. (Courtesy: Jeff Henry)![\"The](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/10\/fire-2-10-10-25.jpg\")
The massive wildfires in the summer of 1988 changed Yellowstone National Park forever. (Courtesy: Jeff Henry)Arrow leftArrow rightWolves Changed Everything<\/p>\n
Wolves were reintroduced to Yellowstone and remote wilderness areas in Idaho in 1995-1996.\u00a0<\/p>\n
They quickly took over the basin areas near Old Faithful. They would drive elk and sometimes bison into deep snow for easier kills.\u00a0<\/p>\n
Eventually, the elk cleared out of the area, Henry said.<\/p>\n
The bison also diminished in number. The old pattern was that about\u00a0two-thirds\u00a0of Yellowstone Bison would hang out in the Hayden Valley and Firehole Basin, in the central part of Yellowstone. And about\u00a0a\u00a0third\u00a0of them would be to the north, in the Lamar Valley.\u00a0<\/p>\n
Eventually, that pattern flipped.\u00a0<\/p>\n
Henry said the wolves might have had something to do\u00a0with\u00a0that, but he doesn\u2019t know for sure.\u00a0<\/p>\n
Wolves also make bison carcasses disappear more quickly, he added.\u00a0<\/p>\n
\u201cCoyotes can\u2019t tear into a bison carcass,\u201d whereas wolves can, he said.<\/p>\n
Sometimes, bears will take advantage of wolf kills but driving wolves away from the carcass and claiming it for themselves, he added.<\/p>\n
Changes Since The Days Of Grizzly 1<\/p>\n
Henry said he never got to see Grizzly 1, who was a huge boar (male bear) that lived to be about age 30. He dominated his home range on the eastern side of Yellowstone.\u00a0<\/p>\n
He saw many other bears, however.\u00a0<\/p>\n
He added that grizzlies have become more highly visible over time.\u00a0<\/p>\n
Back when he first started working in Yellowstone, it was rare to see grizzlies near the roadways. And they were almost unheard of in the geyser basins near Old Faithful.<\/p>\n
Now, bears are a common sight in those areas.\u00a0<\/p>\n
Henry thinks that could be because of a combination of factors.<\/p>\n
First, there are more bears.\u00a0<\/p>\n
Also, large males probably dominate the \u201cprime habitat\u201d in remote areas of the park, he said.\u00a0<\/p>\n
That\u2019s pushed more of the lesser bears into areas busy with tourists.\u00a0<\/p>\n
Female bears with cubs might also hang out in busy areas, because they know that the big males are less apt to go there.\u00a0<\/p>\n
Large male grizzlies are known to kill cubs that aren\u2019t theirs, on the chance that the females might go back into heat and mate with them.<\/p>\n
Henry said the winters in Yellowstone are notably shorter than they were when he started. So, grizzlies emerge earlier and stay out later than they used to.\u00a0<\/p>\n
Grizzlies might start popping out of hibernation in February now. And there have been tracks spotted, or sightings of bears in December, he said.<\/p>\n
![\"A](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/10\/Signs-of-Spring-A-grizzly-bear-on-a-winter-kills-bison-carcass-is-a-sure-sign-of-spring-in-Yellowsto.jpeg\")
A grizzly bear hovers around a bison carcass in Yellowstone National Park. (Courtesy Jim Peaco)Not Many Run-Ins With Grizzlies<\/p>\n
Park visitors are warned to not approach carcasses, because grizzlies will claim them, and hungry bears don\u2019t appreciate human company.\u00a0<\/p>\n
So, how did Henry stay safe from getting mauled when it was his job to walk up to carcasses?<\/p>\n
He said he was always mindful of factors such as wind\u00a0direction and was always cautious\u00a0when approaching a carcass.\u00a0<\/p>\n
\u201cI had thousands and thousands of carcass visits over the years, and I never had anything remotely resembling a confrontation with a grizzly while I was doing that,\u201d he said.\u00a0<\/p>\n
Grizzly 83 Almost Got Him<\/p>\n
However, he had an adrenaline-soaked encounter with grizzly 83, in November of 1986.\u00a0<\/p>\n
He was working as a park ranger at the time.\u00a0<\/p>\n
And that November, winter had already settled in hard. Most of his travel was by snowmobile.\u00a0<\/p>\n
About the only people around Old Faithful were a construction crew, who were refurbishing the Old Faithful Inn.\u00a0<\/p>\n
They had a mobile home that served as their \u201cfood shack,\u201d and slept in employee dorms, Henry said.<\/p>\n
One night, he got a call that that a bear was trying to break into the food shack. So he hopped on his snowmobile and went to investigate.<\/p>\n
And sure enough, there was Grizzly 83.\u00a0<\/p>\n
\u201cShe was just pounding the hell out of the door on the food shack,\u201d he said.<\/p>\n
When the irritated bear saw Henry, she came after him.\u00a0<\/p>\n
He gunned his snowmobile and made a run for the dorms, with Grizzly 83 in full pursuit.\u00a0<\/p>\n
\u201cWhen I got up next to one of the dorms, I bailed off the snowmobile and went for the door,\u201d he said.<\/p>\n
\u201cThe door had one of those \u2018slow closer\u2019 hinges on it, that keep doors from slamming,\u201d and he desperately pulled on it, trying to close it before the grizzly got to him.<\/p>\n
He pulled it shut just in time.<\/p>\n
\u201cShe was just outside of the door, looking through the window at me,\u201d Henry said.<\/p>\n
\u201cShe had this look on her face that was like, \u2018You son of a bitch, I almost had you,\u2019\u201d he added.\u00a0<\/p>\n