Cougars in the Sun River area of northern Montana were studied to determine habitat use and food habits. The study area was located in a unique transition zone between the low-elevation Great Plains and the higher elevation ranges of the Rocky Mountain Front. Researchers found that cougars preferred closed-conifer, open-conifer, aspen-conifer, deciduous tree, and shrubland cover types, while avoiding grassland and vegetated rock cover types. Prey was primarily deer, bighorn sheep, and elk. Preferences for bighorn sheep, elk, and mule deer were present during the winter, with white-tailed deer, and smaller mammals comprising most of the summer prey.