Book excerpt: Veteran trailblazer and outdoor activist Tom Thwaites, the author of two other Explorer's Guide 50 Hikes guides to Pennsylvania, has completely revised and updated this guide to the central portion of Penn's Woods. A wonderful area of wild country and wildlife, this region offers a vast network of maintained trail systems, yet is nevertheless lightly traveled. The author has added 11 new hikes to reflect changing trail conditions, and has re-hiked and checked each of the remaining hikes for this fourth edition. Each hike includes a topographical map, information on mileage, rise, and difficulty, and narrative on sights you'll see along the way.