Caltech Mourns the Loss of Trustee Stephen R. Onderdonk (1944–2024)

Stephen R. Onderdonk, retired chief executive officer of Econolite Control Products, Inc. and a member of the Caltech Board of Trustees, passed away on October 29, 2024.

Onderdonk was first named to the Caltech Board of Trustees in 1986. One of the longest serving trustees, he was a member of the Finance, Facilities, and Infrastructure Committee at the time of his death. Previously, he chaired the Buildings and Grounds Committee and served as a member of the Executive Committee, the Investment Committee, the Personnel Policies Committee, the Audit and Compliance Committee, the Conflict Review Subcommittee, the Institute and Alumni Relations Committee, and the Jet Propulsion Laboratory Committee. Heavily involved with the Athenaeum, he served on its Board of Governors and chaired its Audit Committee.

"Steve's leadership and wise counsel shaped the Institute for nearly four decades," says Dave Thompson (MS '78), chair of the Board of Trustees. "He was committed to ensuring that Caltech operations ran smoothly, and he helped to preserve the campus as a landmark in Southern California."

Onderdonk was born on January 25, 1944, in Evanston, Illinois. He received his BA from UC Berkeley in1965 and his MBA from USC's Graduate School of Business Administration in 1967. He then served as a lieutenant in the US Navy from 1967 to 1971, spending one tour as a mine countermeasures officer in Vietnam and two years as a mining officer with Commander Mine Forces Pacific Fleet, Long Beach Naval Station.

After working for a year as a corporate banking officer with United California Bank, he joined the Colwell Mortgage Trust as vice president in 1972. He became manager of the Investment Real Estate Division of the Seeley Company, Los Angeles, in 1975. He completed Stanford University's Small Company Executive Program in 1981 and an additional program through Stanford's Advanced Management College in 1985.

Onderdonk and business partner Mike Doyle purchased the struggling Econolite Control Products in 1978. Within three months, they reorganized and streamlined operations to show a profit, and the business eventually became the nation's largest manufacturer of traffic control equipment. Onderdonk also became president, CEO, and co-owner of Econolite affiliate California Chassis, which manufactured steel enclosures and carts for the electronic and aerospace industries; and he led Pasadena-based sheet metalwork subsidiary Arroyo Holdings Inc. He owned and managed a working cow-calf ranch in Central California and served as an advisor to the animal science department at Cal Poly San Luis Obispo.

Onderdonk was also president of the Natural History Museum of Los Angeles. He served on the boards or as an officer of numerous organizations, including the UC Berkeley Foundation, Polytechnic School, Flintridge Preparatory School, Chandler School, and the San Gabriel Valley Chapter of the Young Presidents Organization. He was a member of the Caltech Associates.

He is survived by his sons, William, John, and Thomas; and other family.