Book excerpt: More than four million people visit the Grand Canyon National Park every year, but most visitors choose not to stray beyond the heavily visited trails or to venture below the Canyon's rims. The rim trails and the routes to the inner canyon offer solitude and expose beauty vastly different from what can be seeing from the developed areas of the Rims. This edition of the Official Guide to Hiking Grand Canyon provides an overview of all the park's major trails, with notations about difficulty levels, conditions, water sources, distances from point to point and elevation gain and losses.