Hikers along the Yellowstone River Trail in Yellowstone National Park. When hiking along running water, which muffles sounds, and in closed-in areas full of vegetation and poor sightlines where people can surprise bears, it's important to have bear spray ready.  Photo courtesy Neal Herbert/NPS
Hikers along the Yellowstone River Trail in Yellowstone National Park. When hiking along running water, which muffles sounds, and in closed-in areas full of vegetation and poor sightlines where people can surprise bears, it's important to have bear spray ready. Photo courtesy Neal Herbert/NPS