To avoid a costly 800-foot (240 m) tunnel through mountainous terrain east of Promontory Summit, Central Pacific engineers mapped an alternate route that still needed to span the deep Spring Creek Ravine.

[3]: 32 150 yards (140 m) east of the Big Fill, the Union Pacific line was also attempting to cross the same ravine.

I would not ride over it for all the money that James Fisk, Jr., expects to realize by his late raid on the Union Pacific.

Since Union Pacific were responsible for the transcontinental route east of Promontory, the track was laid across the Big Trestle.

They opted to move the rail line from the poor-quality Big Trestle to the Big Fill,[3]: 54  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.