Niles Canyon Railway - Niles Canyon Transcontinental Railroad Historic District

Niles Canyon Transcontinental Railroad Historic District

The railway, its right-of-way, and its associated structures were listed on the National Register of Historic Places as the Niles Canyon Transcontinental Railroad Historic District on October 13, 2010. The railway was determined to be eligible under National Register Criterion C to reflect the engineering significance of the resources as fine examples of historic period railroad design, and under Criterion A to reflect its association with the construction of the Original Transcontinental Railroad and its role as an important freight railway in the early part of the 20th Century.

The Period of Significance was identified as spanning from 1865 to 1958. This period was chosen to encompass the commencement of construction of this portion of the Transcontinental Railroad in 1865 to the end of its significance as a major transportation corridor after World War II and the final incorporation of the Central Pacific Railroad into the Southern Pacific Railroad in 1958.

The historic district includes 108 contributing resources and 39 non-contributing resources. Contributing resources consist of every object within the railroad's right of way constructed between 1865 and 1958. These include the track itself, the graded roadbed, culverts, bridges, signals, telegraph and signal pole lines, structures, signs, and fences. Non-contributing resources consist of things built or altered since 1958, and include non-historic track, buildings, a gas pipeline, and a fiber optic line.

The primary contributing resources of this Historic District include the following:

• Sunol Depot This one-story Stick style depot was built to Southern Pacific standard design No. 7 in 1884. Railroads such as the SPRR created standard depot designs to serve the many towns along its lines and represents an early application of standard architectural designs on a large scale. More than economical, this standardization created a predictable experience for employees and customers, and contributed to the company’s branding. A “combination depot” such as this housed facilities for a company agent, freight and passengers in one building and were designed to serve small towns such as Sunol. Out of at least eleven No. 7 depots built by the railroad, Sunol is the last one remaining. It is 19 feet wide and 67 feet long. The roof is divided into two parts with a gable roof over the east end, and an elevated hip roof over the freight room to the west. Decorative scroll cut brackets supported the eaves and similar barge boards adorn the east gable end. The depot is divided into a series of rooms to serve a variety of functions. Starting from the east, the first room is the passenger waiting room. The agents office is next to the west and features a five-window bay on the track side from which the company’s agent would conduct business related to train operations. This room also contained a public counter at which business could be conducted with shippers, and a small ticket window connects this office with the passenger waiting room. The next room was the baggage room and is currently used for storage. Finally, the freight room takes up the rest of the building and is set about forty inches above grade so that its floor would be level with the floor of freight cars and teamsters’ wagons. This room is now used for exhibits and meetings. The freight room had been surrounded on three sides by a freight platform to facilitate the loading and unloading of freight from rail cars that would have been positioned next to this platform. A track had been located north of the building between the platform and the mainline for this purpose.
• Dresser Bridge The current bridge is a four-span structure, which features two early U.S. examples of riveted Warren through truss structures. The current superstructure was manufactured in 1906 by the American Bridge Company to replace the second wood truss at this location, which had been constructed in 1893. The original bridge at this location was completed in 1866 and consisted of two wooden Howe trusses. The original coursed-ashlar sandstone piers from 1865-66 are still in use and have been supplemented by concrete piers from 1893 and 1906. The bridge consists of two 125 ft. through Warren trusses and two 60 ft. deck plate girder spans with one at each end of the bridge. The abutments and piers are angled parallel to the course of the river below and are not perpendicular to the railroad’s alignment. As a result, the bridge spans are laterally offset from one another.
• Farwell Bridge This bridge consists of the primary 196 ft. Pratt through pin-connected truss manufactured by Edge Moor Bridge Works in 1896, a 98 ft. Warren through pin-connected pony truss, three 30 ft deck plate spans from 1907, and a 70’ deck plate girder span from 1932. The original bridge at this location was also a single-span covered wooden Howe truss similar to the spans at Dresser. Stonework for two of the bridge’s piers dates to the original construction in 1865-66 while later concrete piers and abutments were added in 1896, 1907, and 1932. Caltrans encased the original eastern pier in steel and concrete in the 2000s to protect the highway below in the event of an earthquake. As at Dresser, the piers are at an angle to the bridge, and the spans are offset as a result.
• Arroyo de la Laguna Bridge Near the station of Bonita, this is a riveted through plate girder structure of five spans, which replaced the original covered Howe truss in 1899. The stone abutments and two of the piers date from the initial construction. This bridge consists of three 101 ft. and two 86 ft. through plate girder spans. Two additional concrete piers were added in 1899 to reduce the length of the new bridge spans.