Lesley Wischmann: My favorite historic site in Wyoming has to be South Pass and, more broadly, the whole Greater South Pass Historic Landscape. It has all those wonderful attributes of the best of the historic trails – good remaining ruts, emigrant signature panels, gravesites and unmarred views of trail landmarks. South Pass itself wows me simply by its existence – that remarkably gentle, low natural saddle across the Continental Divide, which was vital for allowing wagons to go west. But even more importantly, when I visit that area, I think about how American history would have been altered had there been no South Pass. Without South Pass, there's no westward migration and our nation's entire history changes. South Pass was pivotal in shaping post-1840 American history, making Wyoming a vital player in our nation's story.