Golden Spike National Historical Park preserves 2,735 acres (1,107 ha) around a 15-mile (24 km) segment of the original first transcontinental railroad at Promontory Summit, on the remote high desert at the north end of the Great Salt Lake in Box Elder County, Utah. It marks the spot where, on May 10, 1869, the Central Pacific Railroad building east from Sacramento and the Union Pacific Railroad building west from Omaha met and drove the ceremonial last spike — the "Wedding of the Rails" that linked the United States coast to coast by rail.

The original Promontory line was bypassed by the Lucin Cutoff in 1904 and its rails were pulled up in 1942 for the war effort. Today about 2 miles (3.2 km) of authentically rebuilt 1869-style track run from the Last Spike Site to the Engine House. Preservation of the site was championed for decades by Bernice Gibbs Anderson, whose Golden Spike Association held its first re-enactment on May 10, 1952. Congress authorized federal ownership in 1965, and the site was redesignated from national historic site to Golden Spike National Historical Park on March 12, 2019.

The park's signature draw is its pair of fully operational replica steam locomotives — the Central Pacific's Jupiter and the Union Pacific's No. 119, both 4-4-0 "American" types. Built by O'Connor Engineering Laboratories of Costa Mesa, California, from more than 700 new drawings based on 1869 photographs, the replicas were commissioned on May 10, 1979, the 110th anniversary of the ceremony.

The classic photograph comes at the Last Spike Site when the Jupiter and No. 119 face each other pilot-to-pilot on the rebuilt track, echoing Andrew J. Russell's famous 1869 "East and West Shaking Hands" image. Mornings during the 10:00 and 10:30 AM engine arrivals and the 1:00 PM demonstration run offer the best chance to capture both locomotives under steam. The polished brass, bright paintwork, and open desert backdrop of the Promontory basin make for striking color images. The Chinese Arch, the Southern Pacific monument, and the open railroad grade of the auto tours provide additional vantage points.

For railfans, Golden Spike is hallowed ground: the exact place where the first transcontinental railroad was completed. Its two working replica locomotives, the Jupiter and No. 119, are the centerpiece. The originals — Jupiter, built by Schenectady Locomotive Works in September 1868, and No. 119, built by Rogers Locomotive and Machine Works of Paterson, New Jersey, in November 1868 — were both scrapped in the early 1900s for a scrapper's fee of about $1,000 each. The modern replicas were reproduced to within a quarter inch of the originals' dimensions.

From May 1 through October 14 the two engines are steamed daily (except on boiler-wash days) and run on the rebuilt track, with the Jupiter arriving at 10:00 AM, No. 119 at 10:30 AM, and a demonstration run of both locomotives at 1:00 PM. Note that the park does not offer train rides — the engines are demonstrated, not ridden. Ranger-led and self-guided tours of the Engine House explain how the locomotives work and how they are maintained using period methods, including boiler-washing.

Beyond the locomotives, the park interprets the human story of the railroad, including the Chinese laborers whose work is honored at the Chinese Arch (renamed in 2006), the Central Pacific's "Ten Miles of Track Laid in One Day" record on the west slope, and the Big Fill and Big Trestle earthworks on the east slope.

Golden Spike is a remote, open high-desert site rather than a crowded museum campus. The 3,000-square-foot Visitor Center offers exhibits, a bookstore, picnic areas, and a seven-minute introductory film. From the Visitor Center it is a short walk to the Last Spike Site, marked by a polished wooden tie and commemorative plaque where the rails were joined.

Plan your day around the locomotive schedule: arrive before the 10:00 AM engine arrivals or the 1:00 PM demonstration run to see the Jupiter and No. 119 in steam. On summer Saturdays from Memorial Day weekend through Labor Day weekend, costumed rangers and volunteers stage a Living History re-enactment of the 1869 Last Spike ceremony following the morning and afternoon demonstrations. In late December the park hosts its annual Winter Steam Festival with cab tours, handcar rides, and Junior Ranger activities.

Services are scarce: fuel, food, and other amenities are not available within 27 miles (43 km), cell coverage is limited, and the nearest emergency services are about 35 miles (56 km) away in Brigham City. Come prepared for wind, sun, and rapidly changing weather.