Every winter, thousands of elk funnel into Wyoming's National Elk Refuge near Jackson — packed together at densities that would never occur in nature. Now, a disease that has no cure and is always fatal has arrived in that same crowded landscape, and wildlife managers are confronting one of the most difficult herd management challenges in the refuge's history.

Chronic Wasting Disease Reaches the Refuge

In May 2026, officials confirmed the presence of Chronic Wasting Disease (CWD) on the National Elk Refuge — a prion disease that attacks the nervous systems of deer, elk, and other cervids. Wyoming Public Media reported the detection, which had long been feared given how the refuge operates. There is no treatment and no vaccine. Once CWD establishes itself in a population, it spreads.

The timing could hardly be worse. Research from the U.S. Geological Survey modeled what CWD could do to elk populations at the refuge and the surrounding region — and the projections are stark. Dense, artificially sustained herds are exactly the conditions under which CWD spreads most efficiently. The refuge currently supports what is considered the largest elk herd in the country.

Supplemental Feeding Is at the Heart of the Problem

The National Elk Refuge was established in the early 1900s partly to provide winter forage for elk that had lost natural habitat to agricultural and human development. Supplemental feeding became standard practice — and over decades, it shaped a herd far larger than the landscape alone would sustain. WyoFile noted that the CWD detection has intensified existing conversations about whether the herd's size is ecologically viable, particularly now that a contagious fatal disease is present.

When animals congregate at feed sites, nose-to-nose contact becomes routine. CWD spreads through saliva, urine, feces, and carcasses. The combination of concentrated animals and a prion that can persist in soil for years creates conditions that wildlife disease researchers describe as deeply problematic.

Climate Is Already Changing Elk Behavior

The disease crisis intersects with another shifting reality. During the mild winter of 2025–2026, large numbers of elk left the refuge early, dispersing across the broader landscape rather than remaining at feed sites, according to the Jackson Hole News & Guide. Warmer winters mean elk increasingly forage on their own — which also means CWD-infected animals moving through a wider area, potentially carrying the disease beyond refuge boundaries.

The Federal Government Is Now Weighing Its Options

In August 2026, the U.S. Fish and Wildlife Service released a Draft Environmental Impact Statement examining different approaches to managing bison and elk on the refuge, according to the U.S. Fish and Wildlife Service. The agency is formally considering options that include reducing supplemental feeding, managing herd size, and improving habitat. The Jackson Hole News & Guide reported that one alternative would continue current feeding practices — which wildlife advocates and researchers argue does not adequately address the disease risk now confirmed on the refuge.

The decisions made in this planning process will shape the health of elk and bison populations across the Greater Yellowstone Ecosystem for generations. Public input matters — and the window to influence the outcome is open now.

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