The INL, serves as important winter range to thousands of pronghorn antelope and hundreds of mule deer and elk. These big game animals freely move between the desert and the surrounding mountains and valleys.

Semi-annual aerial surveys of big game species are conducted in January and June.  ESER biologists conduct aerial surveys of the INL from a small airplane flown at half-mile intervals. During the flights, biologists count the number of pronghorn antelope, elk, and mule deer that can be seen from the plane. In addition, they  count game in agricultural fields adjacent to the INL. The data shown is the number of animals observed, not a population estimate.   The numbers are used to show population trends across time.

While elk and mule deer have only been counted in the aerial surveys since the 1990s, pronghorn population estimates for the INL date back to the mid-1970s. The information obtained from these studies is used to estimate wintering and summering populations of elk, deer and pronghorn antelope with sufficient accuracy to assess trends and to meet INL needs to forecast population increases that may result in significant depredation of agricultural areas surrounding the INL.  

Note:  No elk surveys were conducted in 1993 or 1994.