The Big Fill was an engineering project on the

First transcontinental railroad North America's first transcontinental railroad (known originally as the "Pacific Railroad" and later as the " Overland Route") was a continuous railroad line constructed between 1863 and 1869 that connected the existing eastern U.S. rail netwo ...

in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...

. To avoid a costly tunnel through mountainous terrain east of

Promontory Summit Promontory is an area of high ground in Box Elder County, Utah, United States, 32 mi (51 km) west of Brigham City and 66 mi (106 km) northwest of Salt Lake City. Rising to an elevation of 4,902 feet (1,494 m) above sea ...

, Central Pacific engineers mapped an alternate route that still needed to span the deep Spring Creek Ravine.

Events of 1869

In February 1869, the construction firm of Benson, Farr, & West began construction on a raised bed across the ravine. Over two months, 500 workers hauled more than of material to build the rail bed. At its completion on April 26, the fill extended for and up to a depth of . The cuts for the Big Fill required 1,500 kegs of black powder.

Big Trestle

east of the Big Fill, the

Union Pacific The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pac ...

line was also attempting to cross the same ravine. The Union Pacific was several months behind Central Pacific, and opted to build a wooden

trestle ATLAS-I (Air Force Weapons Lab Transmission-Line Aircraft Simulator), better known as Trestle, was a unique electromagnetic pulse (EMP) generation and testing apparatus built between 1972 and 1980 during the Cold War at Sandia National Laborato ...

instead of using an earthen fill, starting on March 28. The Big Trestle was built in 36 days and was completed on May 5, only 5 days before the

golden spike The golden spike (also known as The Last Spike) is the ceremonial 17.6- karat gold final spike driven by Leland Stanford to join the rails of the first transcontinental railroad across the United States connecting the Central Pacific Railroad ...

ceremony at Promontory Summit. The Big Trestle, intended to serve as a temporary measure until a permanent fill could be constructed, was long and high. Since Union Pacific were responsible for the transcontinental route east of Promontory, the track was laid across the Big Trestle. However, shortly after completion, the trestle was faulted as weak; in addition, there was a grade across the trestle and a curve at one end.

Line moved

Because Congress had fixed the point of junction as Ogden, not Promontory, controversy over the control of the segment between Promontory and Ogden ensued, but the two companies eventually came to an agreement to move the junction to Ogden, with Central Pacific compensating Union Pacific for the cost of construction materials and labor. Six months after the completion ceremony, Central Pacific was awarded control of that segment. They opted to move the rail line from the poor-quality Big Trestle to the Big Fill, where it remained in use until the rails were removed in 1942, although main line traffic was moved off the Promontory route in 1903 with the completion of the

Lucin Cutoff The Lucin Cutoff is a railroad line in Utah, United States that runs from Ogden to its namesake in Lucin. The most prominent feature of the cutoff was a railroad trestle crossing the Great Salt Lake, which was in use from 1904 until the late ...

. Today both sites are part of the

Golden Spike National Historic Site Golden Spike National Historical Park is a United States National Historical Park located at Promontory Summit, north of the Great Salt Lake in east-central Box Elder County, Utah, United States. The nearest city is Corinne, approximately east- ...

; a walking trail from the East Grade Auto Tour takes tourists to view the Big Fill and the remains of the Big Trestle.

References

External links

National Park Service: Golden Spike National Historic Site

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*{{cite web , url=http://people.kzoo.edu/~rkoenig/ndi_public/ , author=Koenig, Richard , publisher=Kalamazoo College , title=Contemporary Views Along the First Transcontinental Railroad Rail infrastructure in Utah Southern Pacific Railroad Union Pacific Railroad