The U.S. Geological Survey (USGS) recently added a new chapter to its report on decision analysis in support of the National Elk Refuge bison and elk management plan previously released earlier this year. The updated report presents a science-based evaluation of a proposed management alternative for winter elk and bison feedground operations on the National Elk Refuge. The chapter introduces “Alternative D,” a collaborative strategy developed by the U.S. Fish and Wildlife Service (USFWS) in consultation with federal and state partners to address the growing threat of chronic wasting disease (CWD) in the Jackson Elk Herd.

Located in northwestern Wyoming and part of the Greater Yellowstone Ecosystem, the National Elk Refuge has provided supplemental winter feeding for elk and bison for over a century. However, the recent detection of CWD in nearby areas—including Grand Teton National Park in 2020 and state-run feedgrounds in 2024—has prompted a re-evaluation of current feeding practices.

Alternative D was developed as part of the Environmental Impact Statement (EIS) led by the USFWS, with input from the National Park Service, U.S. Forest Service, and Wyoming Game and Fish Department. USGS evaluated the potential outcomes of this alternative using four modeled scenarios that considered elk population reduction goals and a proposed threshold for halting elk feeding operations when CWD prevalence reaches or exceeds seven percent in the Jackson Elk Herd Unit. The Alternative would maintain bison feeding under all scenarios.

Key findings from the USGS evaluation include:

• Disease Management: Scenarios in which feeding ceased at the seven percent CWD threshold generally resulted in lower disease prevalence and higher elk population sizes over a 20-year simulation period.
• Habitat Use: Three of the four scenarios showed reduced elk-use days on sensitive habitats—such as aspen, willow, and cottonwood—compared to continued feeding. The seven percent trigger scenario led to increased use of willow and cottonwood habitats but reduced pressure on aspen stands.
• Brucellosis Risk: Brucellosis is a globally regulated livestock disease with serious implications for animal and human health, as well as international trade. Scenarios that did not include the seven percent CWD trigger had lower modeled brucellosis transmission risk from elk to livestock than those that halted feeding immediately.

This chapter builds on the initial findings published in early 2025 and reflects the evolving nature of wildlife management in the Greater Yellowstone Ecosystem. By integrating disease surveillance with adaptive management strategies, Alternative D aims to support long-term conservation goals while minimizing risks to wildlife health and habitat integrity.