Leslie Patten had seen grizzly bears, wolves, coyotes, deer, elk, and many other species in her years living next to Yellowstone National Park. Yet, like most visitors, she had never seen a mountain lion—the charismatic yet enigmatic predator also known as a cougar, panther, or puma. She had only detected their ethereal presence on the landscape, which left her pondering where they were and what they were up to. After five years, through her serendipitous encounters with their tracks and scat, the burning question remained: What is the essence of the mountain lion? To understand an animal no one sees, Patten conducted more than one hundred interviews with biologists, conservation groups, state wildlife managers, houndsmen, and professional trackers. Slowly, a picture of the lion’s elusive nature emerged. Ghostwalker presents a complete picture of mountain lions in the West today, uncovering the intimacies of their secretive lifestyle as well as the issues they face in our changing world.