Cougars, which can reach seven feet long including their tail, are powerful enough to take down an elk, though they feed mainly on deer. As their habitat becomes increasingly fragmented by roads and development, young cougars find it hard to disperse. One of the greatest threats to cougars is negative public perception. In Oregon, the Sierra Club is the lead plaintiff in a lawsuit against the U.S. Fish and Wildlife Service to stop a planned experiment that involves killing healthy cougars to observe the impact on elk populations. But there's good news as well: Cougars may be making a comeback in the East, where they were thought to have gone extinct, and populations are growing in western states partly as a result of bans on hunting with hounds.

State threatened, three subspecies are federally endangered.