Lolo Trail, Idaho
By the time they made it across the Bitterroot Mountains in September 1805, the Lewis and Clark expedition had resorted to eating candles. It was the toughest slog on their journey to the Pacific, and evidence of the Corps of Discovery remains visible in this region. The 113-mile Lolo Trail—a series of Forest Service roads and trails—passes through dense forests and mountain meadows, and near campsites used by the explorers. The surest way to sleep-where-they-slept is to sign up with Lewis & Clark Trail Adventures for a one- or multi-day hike. 800-366-6246, www.trailadventures.com

Ala Kahakai, Hawaii
When it's complete, the 175-mile Ala Kahakai (Trail by the Sea), authorized by Congress in 2000, will follow the west coast of the Big Island from Upolu Point to Hawaii Volcanoes National Park. You can get a glimpse into Hawaiian history by hiking an easy 15.4 miles of the Ala Kahakai, along ancient fishing paths that will become part of the big trail. The preview begins at Spencer Beach Park and passes the Puako petroglyph field and some of the last undisturbed shoreline in the islands. 808-974-4217, www.hawaiitrails.org

Bartram Trail, North Carolina
Between 1773 and 1777, naturalist and artist William Bartram rambled through the South, recording ecology for a classic travelogue. (Travels is the book Jude Law clutches throughout the movie Cold Mountain.) His explorations have been memorialized with an 80-mile footpath: The Bartram Trail starts at the Georgia state line, follows the crest of the Blue Ridge Mountains, and ends on Cheoah Bald, where it joins the Appalachian Trail. www.ncbartramtrail.org