The provisional list of reported grizzly bear mortality reached a new single year record in the first 10 months of 2026, with a few weeks left before hibernation.

So far this year, at least 81 grizzly bear mortalities have been reported on the U.S. Geological Survey's Provisional documented known and probable grizzly bear mortalities in the Greater Yellowstone Ecosystem for 2026, topping 2024 (72) and 2025 (75), which were both record years.

Many may see the news as troubling, yet the leader of the nation's top study team for the species isn't panicking. As a matter of fact, he sees higher mortality as a sign of conservation success.

"Larger populations naturally tend to have higher frequency of mortality," said Interagency Grizzly Bear Study Team (IGBST) leader Matthew Gould. "The increase in population size and range means grizzly bears are occupying areas that last saw a bear over 100 years ago, something many folks wouldn’t have believed when grizzlies were listed as "Threatened" in 1975. The conservation and management actions put in place by state, federal, and tribal agencies mean they are facing new challenges related to the conservation success of grizzly bear recovery."

The IGBST leader serves as a technical and science adviser to the Interagency Grizzly Bear Committee and its Yellowstone Ecosystem Subcommittee, but is not a voting member of the committees. The study team is an interdisciplinary group of scientists and biologists responsible for long-term monitoring and research efforts on grizzly bears in the Greater Yellowstone Ecosystem.

The team was formed by the Department of the Interior (DOI) in 1973 as a direct result of controversy surrounding the closure of open pit garbage dumps within Yellowstone National Park during 1968-72. IGBST members are representatives from the U.S. Geological Survey, National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, the Eastern Shoshone and Northern Arapaho Tribal Fish and Game Department, and the states of Idaho, Montana and Wyoming.

This interagency approach ensures consistency in data collection and allows for combining limited resources to address information needs throughout the GYE. Gould said a spike in mortality is relative and, while the provisional reports of mortality are at record levels, the population of grizzly bears is still increasing slightly thanks to high recruitment of nearly 300 cubs per year inside the Demographic Monitoring Area (DMA).

In the ecosystem, the DMA covers the core recovery zone plus surrounding suitable habitat across Wyoming, Montana, and Idaho (more than 48,000 square kilometers), managed largely through data compiled by the study team.

"In general, larger populations naturally tend to have higher frequency of mortality than smaller populations," Gould said.

However, raw mortality counts can be misleading, he added, and must be referenced to population size and, in the GYE, to the demographic monitoring area (DMA), where field-based monitoring of the population takes place.

"Because the frequency of counts can be misleading, we evaluate mortality rates (i.e., number of mortalities as a function of population abundance), rather than the total number of mortalities alone," he explained.

The population estimate for 2025 (approx. 1,055 individuals inside the DMA) indicates continued population growth for the DMA, although at a slower rate, Gould said.

"Although the rate of population growth is slowing, these data indicate that mortality rates continue to be sustainable," he said in an email exchange with the Tribune last week.

Keep in mind, both the population estimate and provisional mortality rate are only for the number of grizzly bears inside the monitoring area and do not include bears wandering outside "suitable habitat."

IGBST’s population metrics are limited to the DMA, so the study team doesn’t have a population estimate for outside the DMA. However, Gould said 32% of the average annual documented mortalities occur outside the DMA and encompasses 28% of the estimated occupied range of the species. The footprint for the species in the ecosystem has stabilized after decades of growth, he said.

"Our estimate of occupied range for 2024 has stabilized compared to the estimated range in 2022. This, along with slowing population growth rates and changes in dependent age survival rates, suggests that the GYE population has demographically recovered and is occupying most areas of ecological and socially suitable habitat," he said.

The drought

One of the biggest factors affecting the species recently is the extended drought. Drought can impact the variation in natural food availability and is always an important factor that affects conflict and mortality patterns, Gould said.

"Late spring freezes when fruiting food items are in bloom can also have an effect," he said.

Wyoming Game and Fish Department large carnivore biologist Luke Ellsbury said (based on anecdotal evidence) 2026 will be remembered as a "pretty substantial" conflict year in the Big Horn Basin. It hasn't just been grizzly bears that have been turning up in surprising places. Black bear and mountain lion conflicts are keeping the large carnivore team running, he said.

"On years like this we kind of have to do a little bit of a triage with calls that come in, just because it's tough to keep up with all of them," he said. "Across the whole state, this has definitely been a higher black bear conflict year than I can remember."

When natural habitat can't supply enough forage for bears, conflicts will increase, Ellsbury explained.

"This combination of a lower natural foods year with a high population density means there's just not as many resources to go around for the bears and it creates a little bit of a higher conflict year because you get bears searching further [from appropriate habitat]," he said last month.

Mortality stats

There are many categories for grizzly bear mortality. The largest category, by far, is agency removals (mostly euthanizations). Thirty-five grizzly bears were euthanized by agencies in cooperation with the U.S. Fish and Wildlife Service, who have the last word on actions involving species listed on the Endangered Species Act of 1973.

There have also been at least 10 grizzly bears killed in vehicle strikes so far this year, including three cubs of the year being killed in one accident while traveling along the North Fork Highway (U.S. Highway 14/16/20W) in late September. Other bears drowned in irrigation canals, were killed by other bears, by hunters misidentifying the species or by poachers, and at least nine deaths are still under investigation.

Because of natural and substantial variation in annual mortality, drawing major conclusions from a single year is difficult, Gould said.

"That’s why the long‑term monitoring conducted by [the study team] is essential for understanding drivers of population dynamics as they related to sources of mortality," he said. "It’s important for the public to remember that all populations experience individual mortality each year. The [study team] tracks and estimates the level of mortality that is sustainable for [the Greater Yellowstone Ecosystem] grizzly bear population. We don’t have population estimates for 2026 yet, but in 2025, the GYE showed positive population growth despite high levels of mortality indicating a robust and resilient population."

Additionally, Gould said it’s important that documented annual mortality be contextualized to whether the mortality occurred inside the DMA, which represents the area where abundance, mortality rates, and demographic recovery criteria are monitored, and to population size.

Gould said the recovery of the species is a great conservation story, accomplished by many dedicated professionals.

"The demographic recovery of the GYE grizzly bear population serves as a testament to the decades of science-based recovery actions by federal, state, and tribal management agencies," he said.