The 1.17 km long Tehachapi Loop is an iconic spiral loop, that passes over itself as it expansions height on the railroad main line from side to side Tehachapi Pass, in south central California. The Tehachapi loop was actually built in the 2nd half of the 19th century as part of Southern Pacific's main line through southern California, which had to cross the Tehachapi Mountain range. It was finished in less than 2 years’ time under the leadership of civil engineer J. B. Harris, Chief of Construction, a significant feat.
Therefore, over 3,000 Chinese immigrant laborers toiled for two years cutting through the solid and hard granite with blasting powder, and then clearing the wreckage using picks, shovels, and horse drawn carts, to lay the Tehachapi Pass Railroad Line. The line, which climbs out of the San Joaquin Valley and through the Tehachapi Mountains to Mojave in the Antelope Valley, was part of the last and final link of the first railroad line linking San Francisco to Los Angeles. Though, maybe no other time was more interesting on Tehachapi than during the steam and passenger era. However, before the 1971 one could witness trains such as Southern Pacific's overnight Owl.
The main purpose of constructing the Tehachapi Loop was to gain elevation at an adaptable gradient, and this has worked so well for closely 140 years that it continues to be used even nowadays. In fact, it one of the hectic single-track mainlines in the world with an average of almost 40 trains passing through the Loop every day. The repeated trains and the remarkable scenery makes the Loop a prime draw for trains potters in the country. The marvelous engineering achievement has earned the Loop the dual status of being a National Historic Civil Engineering Landmark as well as a California Historical Landmark. During the course of the years there have been a number of inspiring photos taken capturing this marvel and the panoramic scenes are quite magnificent.