The Pioneer Historic Byway traverses through southeastern Idaho’s Franklin and Caribou Counties. The 127-mile corridor begins at Idaho’s oldest town of Franklin on the Idaho-Utah state line and winds northward through rich historic and cultural sites, ending at the Idaho-Wyoming border. As the byway stretches north, visit a mixture of high desert and spectacular geologic vistas, mountains and a remote bird sanctuary.
   Within this pristine and bold landscape are a myriad of fascinating places, events and people that contribute to understanding the American West. The Pioneer Historic Byway is focused on telling the many remarkable stories that add to our knowledge of who and what we are as individuals and a nation. The Pioneer Historic Byway route is the shortest traveling distance between Salt Lake City and Yellowstone Park. The Pioneer Historic Byway route is the shortest traveling distance between Salt Lake City and Yellowstone Park.