Promontory is situated in Box Elder County in Utah. The place is notable for the Promontory Summit where the first Transcontinental Railroad of USA was completed in 1869. It is located on an elevation of about 1494 meters above sea level. Promontory is about 51 kilometers west of Brigham City and 66 miles northwest of Salt Lake City. The Promontory Summit was used for 35 years. Though it was an important historic site but became a part of a huge detour undertaken by the central pacific railroads and the Union Pacific Railroads.

Promontory had a temporary city during the building of the railroad. But soon the city was dismantled and the site never had any stable population. The Promontory Summit is now a part of the Golden Spike National Historic site and is supervised by the National Park Service. Though the railroad track is not operative anymore, but a one and half mile section was re-laid for centennial celebrations.

The site is popular with the tourists of its scenic beauty and historical feature. Most of the tourists keep Promontory visit as a part of the itinerary in order to take a close look at this historical site. Now the site is developed as a major tourist attraction of Utah. The National park Services operated replica trains for entertaining the travelers. UP#119 and Jupiter # 60 were the first steam engines of USA. So, the park authorities have named the replica trains after them to make the visitors feel the glorious past of Promontory in a new way.