The Chisos Mountains contain some of the most rewarding day hikes in Big Bend, especially during the summer months when it is too hot to hike at lower elevations in the park. It is not uncommon to see tracks and scat of black bear, mountain lion, and gray fox along Chisos Mountains trails. Carmen Mountain white-tailed deer, rock squirrels, whiptail lizards, spotted towhees, tufted titmice, and Mexican jays are also common in these mountains.