Flying into Kalispell, your eyes dart here and there, trying to take in all the peaks clawing skyward. While this laid-back Montana town is the western gateway to Glacier National Park, it's also seated in the Crown of the Continent, an idea as much as a phrase that captures Rocky Mountain wildness.

Maps unlock the world in front of us...even if we're not standing right in front of the landscape contained on the map we're gazing at. They allow us to wander through the landscape, cross mountains, ford rivers and streams, and envision campsites in the backcountry. And, in the case of a new eBook, they allow us to look into the past of some national park settings.

For more than a century, freight trains have rumbled up and over Marias Pass, skirting the south boundary of Glacier National Park, casting rolling shadows on the Middle Fork of the Flathead River below. Until recently the major threat was a grain car derailment, which on occasion left bears woozy from eating fermented grain. Today a derailment involving a 100-car train hauling highly combustible Bakken crude oil risks an environmental catastrophe unprecedented in National Park Service history.

Looking to save a few bucks? Purchase a Traveler membership and you'll save on river trips, books, lodging, and now on a map to Zion National Park and national park posters. The memberships, at $9.95 for a year, help you save some money, and help you contribute to the upkeep of the Traveler.