Tunnels: Summit (Tunnel 2)

Legends whisper about it. Ghosts haunt it. Gas leaks from it. And rumor plagues it. Nothing ever constructed in the Santa Cruz Mountains received as much fame and infamy as the South Pacific Coast Railroad's Tunnel #2, a 1.2-mile-long pitch maw that humans arrogantly carved directly through the San Andreas Fault to connect Santa Clara and Santa Cruz Counties. Mother Nature was displeased with the railroad in 1880 and fights even today to erase all trace of this presumptious hole bored directly through the heart of the mountains.

South portal of Summit Tunnel, crossing Burns Creek,
c. 1882. [Bruce MacGregor]

When the South Pacific Coast first drafted its plans to build a railroad between Alameda Point and Santa Cruz, management knew that they would have to go through the mountains somehow, but they waited and delayed and hesitated until mid-1878, when grading crews demanded a final alignment. Initially intended to pass into Soquel Canyon via a smaller tunnel to be located further up Los Gatos Creek so as to descend to the city of Santa Cruz via Soquel, railroad superintendent Alfred "Hog" Davis negotiated a deal with Santa Cruz entrepreneur Frederick A. Hihn and lumber magnate William P. Dougherty in September 1878 to divert the railroad to the San Lorenzo Valley first via a longer route through the Upper Soquel, Bean, and Zayante Creek watersheds. Rather than requiring a single tunnel through the mountains, the new route required four including two monstrously long ones, the longer of which would briefly hold the record for longest railroad tunnel in California. That Goliath of engineering was the Summit Tunnel.

Clearing out mud from the western (Wright) portal of the Summit Tunnel after a heavy rain, c. 1890. [Bruce MacGregor]

Construction began in October 1878 under the direction of Edward H. Mix. Around 100 Chinese workers were brought in to mine the tunnel from both sides of the bore and small camps developed at both sites. On the northern end, the worker camp developed into Wright, especially once freight and passenger service began coming to the location around spring 1879. On the other side, above Burns and Laurel Creeks, the town of Highland developed, where workers for both the Summit and the Glenwood Tunnel lived, as well as lumbermen who harvested and cut lumber on behalf of the railroad and Hihn. A steep switch-back road was built above the northern portal (today's Wrights Station Road) and over the ridge to Highland along what became Schulthies Road. Additional roads were extended off the San Jose-Santa Cruz Turnpike to Wright and off Mt. Charlie Road to Highland. Meanwhile, grading crews worked to install track to Wright and prepare the ground for track in the Highland area. All was proceeding as planned.

Reconstruction of the western portal of the Summit Tunnel, spring 1893. [Bruce MacGregor]

Throughout its existence, the Summit Tunnel had three significant problems—flooding, natural gas, and the San Andreas Fault—each of which will be addressed in turn. Ed Mix anticipated the first problem and designed the entire tunnel to slope gently downward from either side. It was an intelligent move that protected the tunnel interior from ever suffering heavy condensation or erosion. What Mix did not anticipate, though, was the intensity of water flowing down the gully above the tunnel at Wright. For whatever reason, surveyors had chosen to place the tunnel directly at the base of a steep gully that seasonally had significant amounts of water flow down it. Every winter for the first fifteen years of its existence, water poured off the top of the tunnel portal, silting the tracks and often throwing heavy debris below.

Work crews putting finishing touches on the new concrete western portal of the Summit Tunnel, 1893. [Bruce MacGregor]

The winter storm in 1893 was unusually bad and the entire portal at Wright collapsed. Early that spring, crews moved in and cleared the tunnel but the decided against rebuilding the wood-frame portal, opting instead for a complete overhaul. They widened the portal to standard-gauge, anticipating the line's upgrade a decade later, and used concrete rather than wood to reinforce the entrance. Furthermore, they installed a large spillway beside the portal to redirect the flow of water away from the mouth of the tunnel. This worked extremely well and the portal survived the San Francisco Earthquake in 1906 and remained in use until the closure of the line in 1940. Unfortunately, when the Army Corps of Engineers dynamited the tunnel in April 1942 on behalf of Southern Pacific, the structural integrity of this older portal did not hold. The entire concrete face fell forward and has been sinking deeper in to the mud ever since. The only part that remained was some of the concrete frame inside the tunnel and half of the adjacent spillway. It remains the only one of the eight railroad portals in the mountains to be lost. Adding insult to injury, Mother Nature has reclaimed the tunnel since the portal's structural collapse and the seasonal gully now runs freely over the top of the tunnel remains and onto its debris pile below. Nature destroyed the tunnel once and humans vainly attempted to holder her back, but she has once again reclaimed it.

The remains of the western portal of Summit Tunnel, 2000s. [Brian Liddicot]

The other two problems that plagued the Summit Tunnel were unexpected. On November 16, 1878, after only a month of drilling, work crews discovered methane gas in the western end of the tunnel. Even as more workers passed out from overexposure, others began discovering coal deposits and oil spots on the ground. Workers began carrying lit candles and torches into the tunnel to burn off the natural gas, but a number of accidents occurred when workers returned after holidays, work stoppages, and Sundays. By January 1879, crews worked in utter darkness and no further effort was put to discovering the specific source of the gas leak. This was a tragic mistake. On Valentine's Day, an explosion shook the mountain and people began fleeing the tunnel, some aflame. Fourteen Chinese workers died and many other workers were severely burned. Work on the tunnel stopped for three months to search for solutions. Eventually, a new Chinese work crew was brought in (the old refused to return to the tunnel) and pipes were installed to pipe fresh air into the tunnel in the hope that the methane would be pushed out the front. Nonetheless, another incident occurred in June when a creosote-treated redwood beam caught fire and burned for two months. The fire spread to other beams and caused a cave-in, leading to another two-month delay.

Chinese worker standing outside the worker barracks near the Summit Tunnel's western portal, c. 1880. [Bancroft Library]

The most notorious incident, however, was that of November 17, 1879. On that date, crews were working in the tunnel when an explosion shot out of the portal like a cannon. Off-shift workers ran into the tunnel to pull out their friends, but another explosion erupted shortly afterwards. According to sources at the time, thirty-two Chinese laborers died that day. Tunnel construction came to a stand-still on both ends and Cornish workers from the New Almaden Quicksilver mines were eventually brought in to finish the job on the Wright side. By this point, the source of the methane leak was discovered and a pipe was hammered into the leak and a lantern installed to keep the gas burning. Electric lighting was also installed overhead to avoid other open flames. No further incidences occurred and the tunnel was finally finished on May 10, 1880. The boring through of the tunnel inevitably aided in air circulation, providing further protection from an explosion. Regardless, when the western portal was rebuilt in 1893, the methane leak, which was not actually that far into the tunnel, was completely cemented over, thereby resolving the issue permanently. Nothing else has ever been said of the leak, but a persistent rumor exists that a seismology group attempted to inspect the tunnel for internal damage after the 1989 Loma Prieta Earthquake but quickly closed the small hole they had made at Wright when high quantities of methane gas was detected on their instruments. The tunnel may well be a ticking time bomb hiding deep in the Santa Cruz Mountains.

Work crews widening and re-boring portions of the Summit Tunnel, 1906-7. [Bruce MacGregor]

Damage to the Summit Tunnel after the 1906 earthquake.
Western portal visible in distance. [Bancroft Library]

One thing that is certainly true is that the San Andreas Fault had no respect whatsoever for the tunnel. When the earth trembled in April 1906, it shifted by five feet within the tunnel. Like the gas deposit, the damage was largely localized to the western side of the tunnel, since the fault was only about 200 feet inside. Due to poor economic conditions after the earthquake, it took over a year to reopen the tunnel. The new structure was standard-gauge, completely re-timbered, and sported a brand-new concrete portal on the eastern (Laurel) side. A brick ceiling was also installed for roughly 300 feet on that side since the soil was primarily weak sedimentary rocks and required additional support. Because of that brick ceiling and the threat of collapse, US Army engineers decided to only blast the tunnel beyond this point, so the first 300 feet of the eastern portal remains even today as one of the most intact Southern Pacific tunnels in the county (the other being the Zayante Tunnel, which remains in use by FileSafe). That being said, it cannot be doubted that the western portal, located much closer to the fault, probably sustained further damage inside. Due to the destroyed entrance and the probable presence of methane, the current condition of the interior cannot be known.

A velocipede in the western portal of the Summit Tunnel, c. 1910s. [Bruce MacGregor]

The eastern portal of the Summit Tunnel,

c. 1930. [Bruce MacGregor]

In the end, the story of the Summit Tunnel is one of tragedy upon tragedy, disaster after disaster. But what people do not discuss is the fact that, from 1907 until 1942, the tunnel did its job without incident. At 6,157 feet, it was the longest tunnel in the county and remained one of the longest in the United States throughout its existence. It began life as a narrow-gauge tunnel on a relatively short-line railroad and ended as a standard-gauge tunnel on a major branch line of the Southern Pacific octopus. Each disaster strengthened it until it became impervious to most threats. Its solid redwood interior—completely replaced and upgraded in 1907—ensured its durability. Its ultimate closure and inglorious destruction in 1942 were not due to the tunnel, but due to short-sighted business decisions by an over-extended railway company. Most of the tunnel probably survives beyond its collapsed entrances, and the eastern end certainly has plenty to offer visitors even if the line never reopens. But rest assured: if the line over the Santa Cruz Mountains is reopened, the old Summit Tunnel will rise to the occasion once again and Mother Nature will inevitably fight against its survival every step of the way.

The brick ceiling of the eastern portal of the Summit
Tunnel showing few signs of aging, 2012. [Derek Whaley]

Geo-Coordinates & Access Rights:

Western Portal: 37.138˚N, 121.948˚W

Eastern Portal: 37.123˚N, 121.964˚W

The site of the western portal of the Summit Tunnel is easily accessed from the bottom of Wrights Station Road, which is off Morrell Road on Summit Road. Just before crossing the bridge over Los Gatos Creek, the path to the portal can be found. Look for mailboxes and follow the short trail up the gully. The portal cannot be missed. Visiting this tunnel, however, is considered trespassing by the San Jose Water Company and they will ticket any vehicles it finds parked within their area. You have been warned!

The site of the eastern portal is currently unavailable to the public by special request of the owner. In any case, the tunnel was partially flooded in the January-February 2017 storms and the primary two trails to the tunnel have both suffered heavy damage and must be repaired before they should be used. The new property owners hope to allow access to the site at some point in the future. Check back on this page for future information.

Citations & Credits:

• MacGregor, Bruce A., and Richard Truesdale. A Centennial: South Pacific Coast. Boulder, CO: Pruett Publishing, 1980.
• Whaley, Derek R. Santa Cruz Trains: Railroads of the Santa Cruz Mountains. Santa Cruz, CA, 2015.