Detecting the presence of a mountain lion (cougar) requires a keen eye for subtle "tracking" signs, as these predators are famously elusive "ghost cats." The most common indicator is scat—typically about an inch in diameter with blunt ends, often containing hair or bone fragments. Unlike dogs, mountain lions frequently leave "scratch piles" (mounds of dirt, leaves, and pine needles) that they urinate on to mark their territory. You should also look for tracks: cougar paw prints are about 3 to 4 inches wide, have four toes with no claw marks (as their claws are retractable), and a three-lobed "heel pad" shaped like an "M." If you find a "cache"—a deer or other prey that has been partially eaten and then covered with leaves and brush—a mountain lion is almost certainly nearby and will likely return to finish its meal. In 2026, hikers are advised to never wear headphones and to listen for the "chirping" or "whistling" sounds that cougars use to communicate, which can be easily mistaken for birds but indicate a large predator is moving through the area.