America's national parks are full of beauty and natural wonders, but they're also home to many things that can strike fear in the hearts of hesitant hikers: dark caverns, wild animals and complete isolation. For the most part, there's nothing to fear, but if you're looking to add a little spooky spice to your next outdoor adventure, check out these eight parks. Local legends, historic hauntings and creepy creatures make these national parks the perfect places for Halloween hikes. (Text: Laura Moss)