In 1927, Baldwin Locomotive Works rolled out a giant. They called it No. 3751. This massive machine didn't just pull cars it completely changed how the Santa Fe Railway moved people across the American West. Before this 4-8-4 "Northern" type arrived, smaller locomotives struggled on the steep mountain grades. No. 3751 solved that. With 66,000 pounds of tractive effort, it easily hauled fifteen-car steel passenger trains over the Cajon Pass. It burned oil instead of coal. This simple fuel switch saved the railroad a fortune, and it meant fewer stops for servicing along the route.

Diesel engines eventually took over in the 1950s, sending steam to the scrap yards. But 3751 escaped the torch. The railroad parked it in a San Bernardino park in 1958, where it sat gathering rust and cobwebs for decades. Then, volunteers stepped in. They spent years turning greasy wrenches and raising cash to rebuild the boiler. In 1991, they fired it up again. Today, it stands as the oldest surviving 4-8-4 locomotive in America. When it stretches its legs on mainline excursions, the sight of its massive 80-inch driving wheels spinning draws thousands of screaming fans. It isn't just a static display. It is a roaring, steam-belching giant that still commands the rails.