Central Pacific Railroad (CPP) began work on the western portion of the transcontinental railroad in Sacramento on January 8, 1863. By the spring of 1864, workers dug a railroad grade with picks shovels for 33 miles towards the northeast until they encountered their first significant obstacle in the form of a long, tall ridge at Bloomer Ranch about 1 mile short of reaching Auburn. Engineers could not design the railroad to climb over the ridge because it was too steep of a grade for railroads. Therefore engineers designed a railroad bed that would penetrate 800 feet through the ridge and cut as deep as 63 feet at the center of the ridge. Normally, going through such an obstacle would not be a problem, but this ridge was made of a rock suspended in clay, which effectively formed a massive, natural, concrete wall. The natural concrete broke picks, shovels, and other equipment, and therefore CPP decided to use black blasting powder. But even blasting proved difficult because holes needed to be drilled into the hard concrete-like rock for holding the powder.
The crews used 500 kegs of black powder per day, which proved to be an expensive and dangerous proposition. Indeed, one explosion blinded the left eye of the famous, energetic, tall, Irish foreman, Harvey Strobridge after he attempted to prepare 50 pounds of powder. The Chinese respected Strobridge, and those who learned English called him “Stro” or the “One-eyed bossy man.” Strobridge respected the Chinese workers after working a month with them. He stated, “They learn quickly, do not fight, have no strikes that amount to anything, and are very cleanly in their habits. They will gamble and do quarrel among themselves most noisily – but harmlessly.” The chief engineer, a big supporter of Chinese workers, stated “The Chinese are faithful and industrious and under proper supervision soon become skillful in the performance of their duty. Many of them are becoming expert in drilling, blasting, and other departments of rock work.”
Ultimately, workers removed over 40,000 cubic yards of material, and completed the grade and tracks through Bloomer Cut in the spring of 1865. The first train reached Auburn from Sacramento on May 13, 1865, and Bloomer Cut was considered a great engineering feat to merit the title of the “Eighth Wonder of the World.”
Although the narrow pathway through Bloomer Cut does not follow current day railroad clearance standards, regulators made an exception to the Bloomer Cut clearance because the walls were so solid. The concrete-like walls have preserved Bloomers Cut well, and Bloomers Cut looks virtually the same as it did in 1865. However, development did threaten Bloomer Cut; developers proposed a bridge over Bloomer Cut and widening Bloomers Cut for another track. Fortunately, none of these proposals moved forward. However, the threat of development remains on the vacant land across from Bloomer Cut.
Now trains generally move westerly through Bloomer Cut while trains move east on another set of parallel tracks about 0.5 miles north of the Bloomer Cut.