Mule deer herds continue to recover

According to a March 18 Wyoming Game and Fish Department (WGFD) update, mule deer populations across western Wyoming are reporting encouraging signs of recovery as they rebound from significant losses caused by the severe winter of 2022-23.

The department notes both the Wyoming Range and Sublette mule deer herds have demonstrated strong population growth, high survival rates and improved reproductive success over the last several years.

“Both herds have demonstrated incredible resilience over time, rapidly recovering from periodic high winter mortality, as we saw in the mid-2000s and, more recently, from 2011-16 when consecutive mild, open winters resulted in high survival and rapid population recovery,” states Brandon Scurlock, WGFD wildlife management coordinator for the Pinedale Region, in the corresponding press release.

Research and monitoring 

According to WGFD, data has been compiled through a collaborative long-term study with the University of Wyoming’s (UW) Monteith Shop and an ongoing focal herd study conducted by the department.

The UW study is working to understand factors regulating survival and reproduction of the Wyoming Range Herd, while the five-year WGFD study, now in its fourth year, is narrowing in on five herds across Wyoming to gather information on the causes of population declines and possible solutions. 

“From these studies, researchers from the UW Monteith Shop and WGFD biologists are learning more about how the landscape influences population dynamics,” the brief reads. 

In addition, WGFD biologists have been using a combination of GPS collaring, biological sampling and habitat analysis to better understand how landscape conditions affect herd dynamics, which helps the department shape mule deer management decisions.

Feedback collected from post-season hunter surveys is another key tool in population monitoring. The department notes these surveys provide insight into harvest totals, hunter success rates and public perception of herd health, which helps set future quotas and establish season dates.

“For the 2025 season, hunter success in the Wyoming Range Herd was 27 percent and 29 percent in the Sublette Herd,” WGFD states. “Although some hunter comments still indicate low deer numbers, post-season classification data shows signs of population growth and high productivity.”

Population growth

Overall, WGFD says recent data collected through research efforts and department monitoring suggests recovery of mule deer in western Wyoming herds is being driven by survival – which biologists contribute to a stretch of relatively mild winters and reduced snowpack allowing deer better access to forage on winter ranges – as well as strong reproduction.

In fact, surveys conducted this past winter showed “incredibly high” fawn and buck ratios in both herds.

In the Wyoming Range Herd, biologists observed 81 fawns per 100 does in 2025, following 83 fawns per 100 does the previous year. 

Buck ratios climbed to 38 bucks per 100 does, bringing the buck ratio to objective. 

“This productivity is reflected in an increased population estimate of 15,500 for the 2025 post-hunting season, up from 13,200 in 2024,” WGFD says.

In the neighboring Sublette Herd, the population is also trending upward. WGFD recorded 77 fawns and 43 bucks per 100 does, with the population estimate rising 18 percent to 22,437 animals.

Researchers attribute part of this success to improved body condition among deer. 

“Heading into this winter and during fall capture efforts, researchers recorded above-average body fat levels and the highest number of females successfully recruiting twins ever recorded since data collection began in 2016,” WGFD adds.

While challenges such as harsh winters and habitat conditions remain ongoing concerns, the current trajectory of both herds is encouraging. WGFD notes continued favorable weather, strong reproductive performance and data-driven management are expected to support further recovery.

Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.