When discussing the history of railroading in the Tehachapi area, there is little doubt that the star of the show for rail enthusiasts is California Historical Landmark No. 508, otherwise known as the Tehachapi Loop. Constructed between 1874 and 1876, this civil engineering landmark made up of a three-quarter-mile-long spiral allowed locomotives to finally conquer the daunting Tehachapi Mountains, opening up a route that would reach Tehachapi and Mojave before branching off to Southern California and eastward.

Steve Smith, who serves as a docent at the Tehachapi Depot Railroad Museum, and as a member of the museum’s governing board, said those who have wanted to see the Loop over the years have simply pulled over at the Tehachapi Loop Overlook on Woodford-Tehachapi Road, near Keene.

“We sometimes have tour buses with 40 people stop there,” he said.

Plans to construct a fenced viewing area at the site have been approved and the improved overlook is slated to be completed in summer 2021.

The loop and the Southern Pacific Railroad line was built by Chinese immigrant laborers, on a 2.2 percent grade to Tehachapi’s summit.

That means for every 100 feet of track, the elevation could rise 2.2 feet. That was the design restraint, said Doug Pickard, who has volunteered as curator and in other capacities at the museum for years.

It took at least 17 tunnels and several bridges (or creek crossings) to complete the line, Pickard said. Some of those tunnels were damaged or destroyed in the 1952 earthquake or were bypassed by later track construction.

The Southern Pacific Railroad was extended to Mojave and across the Antelope Valley, reaching Los Angeles through Soledad Canyon and the San Fernando tunnel.

The construction of the Southern Pacific Railroad line through Tehachapi would become vital to the growth of Los Angeles and remain an important part of Tehachapi’s history.

The Southern Pacific Railroad, which monopolized California’s railroads at this time, eventually found a rival in the Santa Fe Railway. Eyeing a line that would cross the Tehachapis from Bakersfield up to Tejon and Chanac Creeks, Santa Fe and Southern Pacific would come to an agreement in 1899 that let Santa Fe trains use the Tehachapi grade. The Santa Fe line no longer needed to be built.

In 1996, Union Pacific absorbed Southern Pacific, and Burlington Northern Santa Fe succeeded the Santa Fe. Today, the two continue to operate the Tehachapi line.

The track hasn’t changed much since it was built more than 140 years ago. It’s still one of the busiest runs of single-track railroads in the West, with about 35 trains a day on the famous Tehachapi Loop.