This famous locomotive is known as a "Northern" type due to it's 4-8-4 wheel arrangement. Known on the Union Pacific as an FEF-3, the class was equiped with 80" driving wheels making it ideal for fast passenger service but was equally at home hauling freight. The locomotive has the distinction of being the only mainline steam engine to have never been retired from active duty. Union Pacific lovingly maintains the engine today and she is regularly operated on public relations tours and railfan excursions.