Sentinel over Silicon Valley. Photo: Courtesy of Jitze Couperus

It was a clandestine military post, a mysterious mountain tower, and a secret control room filled with the blips and bleeps of sci fi-worthy technology. During the Cold War, the radar tower atop Mt. Umunhum embodied the stuff of Cold War fantasy. Besides guarding the Santa Clara Valley from Soviet bombers, the post was a catalyst for technological advances that paved the way for today’s Silicon Valley.

Yet after 22 years of protecting the valley, the long-decommissioned tower is now the subject of an impassioned debate about its future.

The boxy radar tower atop Mt. Umunhum. Photo: Basim Jaber Photography

How Silicon Valley Learned to Stop Worrying and Love Radar

By the end of World War II, the rivalry between the US and the Soviet Union had heated up enough to kick-start the Cold War. The Soviet Union detonated their first atomic bomb in 1949 and, as the former regime began annexing Eastern European countries, US officials began planning an expansive air defense system to secure the country’s perimeter. Until the advent of intercontinental ballistic missiles, the biggest threat to American shores was airborne, nuclear-armed bombers.

In 1958, Almaden Air Force Station was founded as an early warning site at Mt. Umunhum, the fourth-highest peak in the Santa Cruz Mountains. (If you think the Soviets didn’t have their eyes trained on the San Francisco Bay Area, take a peek at this fascinating Cold War era map.) Named for the Ohlone Indian word for “resting place of the hummingbird,” Mt. Umunhum became the site of a self-sustaining military community — complete with swimming pool and bowling alley — of 125 airmen and their families. At the center of the station, a spinning radar swept the skies for hostile aircraft.

Keeping watch at the radar tower, 1964. Photo: Basim Jaber Historic Archives

This was not the first radar in the Santa Clara Valley. Stanford University, Moffett Field naval air station, and nearby defense-funded technology firms made the valley the home of numerous radar advances and military research in the early 20th century. In the 1930s, Stanford University initiated a pioneering research park and invited Varian Associates to be its first tenant so that it could build radar components for the military.

Operations room, 1960. Photo: Basim Jaber Historic Archives

Yet when Almaden was opened, radars were still manual, isolated, and couldn’t offer the panoptic view that defense officials craved. Enter IBM’s Military Products Division. Eager to win a significant post-war military contract, the computing giant linked radars by designing the world’s first computer network, something that would herald the modern Internet.

SAGE-Topped Mountains

In 1961, The Almaden Air Force Station became part of an innovative nationwide network dubbed SAGE, for Semi-Automatic Ground Environment. Engineered by IBM, SAGE was a series of interconnected computers that captured info from radars around the nation to form one central picture of US airspace. This data was fed to the North American Aerospace Defense Command, known as NORAD, as information for a military response via jets or missiles from nearby bases.

Clouds over Mt. Umunhum. Scene from Santa Teresa County Park. Photo: Don DeBold

SAGE had the distinction of being the largest, most expensive computer system ever built and the first online network of geographically distributed computers in the world. The station atop Mt. Umunhum was one node in a network of 24 SAGE “direction centers.” The central building in each center was a windowless blast-resistant concrete behemoth. Known simply as Building 102, the center at Mt. Umunhum was topped with a massive 85-ton radar “sail” that oscillated and covered a whopping 250-mile range. Local residents soon learned to live with a regular zip of interference on radios and television screens as byproducts of the radar that stood sentinel high above the valley.

SAGE Display Scope. Photo: Joi Ito

The enormous SAGE computers filled a room and required a staff of 100 to operate. Airmen sat at round monochromatic screens, or display scopes, with pulsating lights that made Pong look cutting-edge. The SAGE computer system was captured in two time capsule-worthy films produced by IBM: A TV commercial that introduced the system to the public and “On Guard!,” a 12-minute short with a paternal narrator who reminded us that SAGE was on the job around the clock.

The real SAGE computer displayed at the Computer History Museum. This is a great museum in Mountain View. Click here for hours. Photo: Steve Jurvetson

At the Movies

SAGE didn’t just star in propaganda shorts. It made appearances in feature films, including the Cold War satire “Dr. Strangelove,” where it surrounds a frantic Peter Sellers trying to stave off nuclear Armageddon. The wheelchair-bound character of Dr. Stangelove was based on one of the architects of SAGE who was also principal member of the Manhattan Project, John von Neumann. As SAGE was dismantled, pieces were used as set props in movies such as “Lost in Space,” “Planet of the Apes,” and “War Games,” a sci fi flick that pits an unknowing hacker against a nuclear-ambitious supercomputer in Sunnyvale, California.

Open Space and the Fight for Preservation

As technologies advanced and satellites began to eclipse radars, the staff at Almaden dwindled and the station was ultimately shuttered in 1980. In 1986, it was sold to the Midpeninsula Regional Open Space District, or Midpen, a Bay Area land preservation agency. Midpen is in the process of restoring the land to its natural state so that the previously restricted property can be enjoyed by the public as an open space preserve. In 2011, KQED detailed the restoration project in an engaging 10-minute film. The new park is scheduled to open on October 22, 2016 with interpretive trails, natural and cultural history exhibits, and sweeping top-of-the-world views.

Mt. Umunhum from Almaden Lake in San Jose. Photo: Basim Jaber Photography

Given the time-worn disrepair to the radar structure and a lack of a background in historic preservation, Midpen announced plans to demolish the iconic tower, the last remaining structure on the former air force station. In 2014, the Santa Clara Valley unexpectedly lost a similar Cold War landmark, the boxy operations center used for tracking spy satellites from the former Onizuka Air Force Station in Sunnyvale — what locals called The Blue Cube. It was demolished in 2014.

The threat to the Almaden radar tower mobilized a group of individuals to form the Umunhum Conservancy to help save the structure. Midpen agreed to halt plans to raze the tower if the conservancy could raise $1.5 million by 2017. Basim Jaber, a founding director of the conservancy and de facto historian of Almaden AFS, is a strong advocate of the tower’s preservation. In advocating for the significance of saving the atomic age icon, Basim states, “Not only did air defense technology help shape Silicon Valley, it contributed to the blanket of protection that let this valley thrive to what it is today.” Jaber brings the Almaden Air Force station back to life in vividly detailed slideshows presented every other month. Held at the Quicksilver Mining Museum, in the shadow of Mt. Umunhum, the free demonstrations are buoyed by Jaber’s extensive collection of historical photos and archives. For a schedule of upcoming slideshows, check the conservancy’s website.

The effort to save the radar tower has recently made great strides. The Santa Clara County Board of Supervisors voted on May 10, 2016 to put it on the county’s Heritage Resource Inventory, a designation making it immune from demolition as long as the building is cared for and not falling down. The Umunhum Conservancy plans to take great care of it. As of May 2016, they have raised about $375,000 toward their $1.5 million goal.

Mt. Umunhum sunset. Photo: Dawn Ellner

Be sure and check out this Cold War gem and the surrounding hiking trails when Midpen opens the area to the public. It was scheduled to open on October 22, 2016, but has been delayed to mid-next year due to construction delays and increased costs. When it does open, Basim Jaber has graciously offered to give Mobile Ranger fans a guided hiking tour after it opens. If you are interested, please say so in the comments section that follows.

Updated October 24th, 2016

Sentinel of Silicon Valley: The Radar Tower at Mount Umunhum is Saved https://t.co/4S1tRrGmK1 @HistorySanJose pic.twitter.com/GU9oYHWuvT

— Mobile Ranger (@Mobile_Ranger) October 24, 2016

Replica of first integrated circuit by Jack Kilby. Photo: Florian Schäffer CC BY-SA 4.0

The integrated circuit might not inspire the same level of excitement as other tech breakthroughs, such as Facebook or the iPhone, but the impact of its invention was just as far-reaching, if not more so. You don’t need an engineering degree to understand how it changed everyday life. In fact, if you’re reading this on a smartphone, tablet, or laptop, you’re benefiting from the integrated circuit.

The first commercially viable integrated circuit was invented in Silicon Valley and was fundamental to both naming the region and making it today’s powerhouse of technical invention. Two plaques at the entrance to the former site of the Fairchild Semiconductor building in Palo Alto, California pay homage to the circuit’s significance.

Former Fairchild Semiconductor building at 844 Charleston Road, Palo Alto, California. The historical markers are  to the right of the door shown in the center of the photo. Photo: Garrick Ramirez/Mobile Ranger

Closeup of the two historical markers at the right of the door in the center of the photo. Photo: Garrick Ramirez/Mobile Ranger

OK, But What Is an Integrated Circuit?

An integrated circuit is an interconnected series of electronic components that are fitted onto a plate the size of a fingernail. It’s also referred to by the more familiar term, the microchip. Integrated circuits are at the heart of most electronics. They perform the core functions of everyday devices, such as smartphones, cars, and ATMs. A microprocessor, the virtual brain inside a computer, is one example of an integrated circuit.

The introduction of the integrated circuit was revolutionary because it made both personal computing and handheld electronics possible. Before integrated circuits, computers filled rooms that resembled a digital Dr. Frankenstein’s lab. For the first half of the 20th century, most electronics functioned on bulky vacuum tubes until the smaller and more efficient transistor was invented. The shift to transistors shrunk circuit boards significantly but not enough to make something like a handheld calculator possible. That all changed with the integrated circuit.

Robert Noyce with Motherboard, 1959. Photo: Intel Free Press CC BY SA 2.0

The Revolution Began with the Traitorous Eight

The story starts with the Traitorous Eight. What sounds like the title of a Quentin Tarantino flick refers instead to eight employees of Shockley Semiconductor Laboratory in Mountain View, California who fled to form their own semiconductor company in 1957. Word on the street was that owner William Shockley, co-inventor of the transistor, was a genius but a less-than-personable boss. The eight men christened their nascent company Fairchild Semiconductor and formalized the partnership by adding their signatures to a set of newly minted one dollar bills.

The Fairchild/Shockley 8, who left the lab of Nobel Prize winner William Shockey to form Silicon Valley’s first start-up, Fairchild Semiconductor, 1960. From left to right: Gordon Moore, C. Sheldon Roberts, Eugene Kleiner, Robert Noyce, Victor Grinich, Julius Blank, Jean Hoerni, and Jay Last. Photo: Wayne Miller © Magnumphotos.com, used with permission

It was at Fairchild that the current model for the microchip was invented. Robert Noyce, one of the Traitorous Eight, created what was referred to as a monolithic integrated circuit. Rather than a traditional circuit, where individual components — transistors, resistors, and diodes — sat atop a large plate, linked by wires, Noyce’s integrated circuit was one self-contained plate. Using a semiconductor, a substance of exceptional insulation and conductivity, the components were fabricated from and within the plate itself. This enabled the circuit to be much smaller and much faster. For his integrated circuit, Noyce used silicon, the primary element in sand and the material still used to produce microchips. It’s also the substance that eventually redefined the Santa Clara Valley.

Silicon Proves More Fruitful Than Peaches

In the early 20th century, the Santa Clara Valley was blanketed in fruit orchards that supplied the nation with most of its apricots, prunes, and peaches. Long before Apple and Google, the big names in the valley were Del Monte and Sunsweet. But after the rise of Fairchild, the number of semiconductor manufacturers began to proliferate. Many of those companies were formed by former Fairchild employees.

Prune Orchard Near Santa Clara, California. Photo: Oregon State University Special Collections & Archives

So influential was Fairchild that employees who left to form other companies were dubbed The Fairchildren. Noyce and his associate Gordon Moore eventually left Fairchild to start Intel, which later developed the first commercially viable microprocessor. By 1971, the number of semiconductor manufacturers in the Santa Clara Valley had grown so prevalent that journalist Don Hoefler referred to the region as “Silicon Valley USA,” and the name stuck. Noyce was even called “The Mayor of Silicon Valley.”

The Nobel Prize Goes to Who?

The historical markers at the entrance of the former Fairchild Building in Palo Alto commemorate Noyce’s groundbreaking feat. But the real credit that counts for the invention of the integrated circuit, which won the Nobel Prize in Physics in 2000 for “basic work on information and communication technology,” went to Jack Kilby, not Robert Noyce.

There’s a story behind that, too, of course: In 1958, roughly six months before Noyce’s discovery, Kilby invented the first integrated circuit when he was a new employee of Dallas-based Texas Instruments. But due to vulnerable wiring and the use of germanium as a semiconductor, Kilby’s circuit was judged commercially unviable. Fairchild and Texas Instruments duked it out for years over the claim to the technology but finally settled upon Kilby and Noyce as co-inventors. Kilby took home the part of the 2000 Nobel Prize relating to integrated circuits, but Kilby did mention Noyce in his acceptance speech.

So Much Moore Than Before

Although Noyce’s pioneering model is still used today, the capacity of microchips has grown exponentially. In 1965, Noyce’s colleague, Gordon Moore, famously predicted that the number of transistors and corresponding processing power in a circuit would double roughly every year for 10 years. In 1975 he revised it to every two years. Although Moore made the prediction partly to encourage more sales of Fairchild Semiconductor chips, the engineers at Fairchild made it a goal to make sure Moore was right.

Moore’s Law says that the number of transistors that can fit into a dense integrated circuit doubles approximately every two years, which doubles the processing capacity. It is named after a prediction by Gordon E. Moore, co-founder of Fairchild Semiconductor and Intel. The transistor numbers trend chart shows major central processing units (CPUs) 1970 – 2011. Graph: shigeru23 CC BY SA 3.0

Moore’s prediction, which came to be known as Moore’s Law, was  prescient well beyond a few decades. In 1959, Noyce’s circuit contained one transistor. Today, microchips contain hundreds of millions.