Grab your hiking boots, the dog, a couple of energy bars, and some water. It’s time to hit one of America’s 60,000 miles of trails in the National Trail System. On November 17, it’s National Take a Hike Day, an annual event designed to get you outdoors for some fresh air, scenery, and exercise. Hiking is a cross-country-long walk to get that heart pumping while you breathe deeply in air that’s not clogged with auto fumes and pollution. You never know what you’ll see out on the trail.