Since the first abandoned rail corridors were turned into trails in the 1960s, more than 15,000 miles of rail trails have been constructed in the U.S. The 30 miles of rail trail between Tetonia and Ashton, Idaho, on the western side of the Tetons south of Yellowstone, might be among the country’s most scenic. Because it’s Idaho, there are potato fields almost as far as the eye can see, as well as wheat fields and stands of aspen trees. But it’s the Tetons looming in the distance—their snaggly profile easily recognizable even in reverse (most images of the range are taken from its eastern face)—that grab your attention. The three beautiful and historic trestle bridges the route crosses are just showing off. Stop in Ashton at the classic Frostop Drive-In for a malted shake and burger.