Supplemental Feeding


As elk gather on the refuge, harsh winter conditions create challenges for the animals and for wildlife managers.

Winter feeding of elk in Jackson Hole began in 1910 and was originally initiated to reduce winter mortality of elk, thereby helping preserve a population of animals important to local residents and interest groups, as well as to minimize depredation of rangers; hay. Although these immediate factors prompted the initiation of winter feeding, the need for the refuge's winter feeding program is a direct result of reduced access to significant parts of elk native winter range. The creation of Yellowstone National Park in 1872 and the National Elk Refuge in 1912 were crucial in terms of protecting elk and their winter ranges in the greater Jackson Hole area. 

Elk were fed hay during at least a portion of most winters from 1912 to 1975. Alfalfa pellets were experimentally tried as supplemental feed for elk beginning in the winter of 1970-71. In 1975, after several years of testing, a switch was made to alfalfa pellets. These pellets have a higher nutritional value than baled hay. 

When deep or crusted snow prevents elk from grazing, or when little natural forage remains, refuge personnel provide supplemental feed. The initiation of feeding in any given year depends on elk numbers, the timing of migration, winter temperatures, snow depths, and the accessibility of standing forage. Biologists evaluate these factors to determine whether feeding is needed, and if so, when it should begin and end. Elk currently are fed an average of 70 days annually.

When animals are clustered in a relatively small area such as the National Elk Refuge, the environment can become contaminated. This overcrowding increases the probability that diseases can spread through the bison and elk herds. Two diseases that are commonly discussed are brucellosis and chronic wasting disease.

In consultation with the Wyoming Game and Fish Department, the U.S. Fish and Wildlife Service has determined a herd size objective of 5,000 elk and 500 bison for the National Elk Refuge in order to avoid overuse of the range and to reduce the spread of diseases.