Russell and Sigurd Varian’s inventions were vital to Allied victory in World War II and helped establish Silicon Valley. Russell was also a prominent conservationist who helped establish Castle Rock State Park.

What does the Royal Air Force’s victory in the Battle of Britain have in common with the establishment of Castle Rock State Park? Russell Varian.

Russell Varian (1898-1959) and his brother Sigurd (1901-1961) were raised in the Utopian community of Halcyon, California by their mystic poet father John Varian and mother Agnes. The Varians were theosophists – freethinkers who have been described by some historians as proto-hippies. As a result, the brothers were raised among artists and visionaries.

After establishing independent careers in electronics and aviation, the brothers responded to the ominous rise of Adolph Hitler in Germany with innovation. The pair work on an all-weather, radio-based navigation system that used microwaves to detect airplanes at night or in clouds. With the help of friend and Stanford professor William Hansen, the brothers ultimately created the klystron, the first tube that could generate electromagnetic waves at microwave frequencies. In 1939, klystron equipment successfully facilitated blind-landing tests of airplanes.

The Varian brothers’ invention was heralded in the Palo Alto Times.

Thanks to the Varians’ timely invention, the British developed the Sutton tube klystron, which gave Royal Air Force pilots the advantage necessary to counter Germany’s night-bombing raids in 1940 and eventually win the Battle of Britain. The brothers would go on to found Varian Associates in Stanford Industrial Park, essentially establishing Silicon Valley.

In addition to his enormous engineering achievements, Russell and his second wife, Dorothy, were prominent conservationists. In fact, Russell died unexpectedly of a heart condition while scouting locations for national parks in Alaska on foot. Before his untimely death in 1959, Russell had secured an option to buy Castle Rock, which he hiked frequently, and planned to donate it to California State Parks.

In the wake of her husband’s death, Dorothy leveraged Sempervirens Fund as a trust to acquire lands for conservation. Her efforts helped establish Castle Rock State Park in 1968. Originally 566 acres, the park now encompasses 5,150 acres of wilderness and 34 miles of trails.

For many years, Russell Varian was a close friend and hiking companion of iconic photographer Ansel Adams. Adams used a line from a poem by Russell’s father, John Varian, as the title of Portfolio IV, which he dedicated to Russell’s memory in 1963. The portfolio, of which only 200 copies were printed, was narrated with the words of John and Russell Varian. Three copies of this portfolio were donated to Sempervirens Fund with the express wish it be used to directly benefit Castle Rock State Park.

In 2019, Sempervirens Fund opened the state-of-the-art Robert C. Kirkwood Entrance, with paved parking, new restrooms, accessible pathways and picnic areas, and more. The 33-acre facility triples the amount of parking, and vastly enhances the user experience with interpretive signs, rentable amphitheater and event space, and running water.

To learn more about the Varian brothers’ inventions, read this May 2017 New Scientist article, “The U.S. inventors who helped the RAF win the Battle of Britain.”

To celebrate Castle Rock’s 50th anniversary in 2018, Sempervirens Fund held a series of lectures in collaboration with our partner, REI. Hear one of those lectures on the Sempervirens Fund Podcast.