Biography
Darald Walter Callahan was born in 1942 in Merrill, Wisconsin. His family moved to Oregon in 1946 and settled in the Roseburg area three years later. A member of the National Honor Society, Callahan took several advanced courses throughout high school. He enrolled at Oregon State College in 1960, majoring in engineering.
As a student at Oregon State, Callahan was involved with student government and was a regular on the honor roll. During his junior year, Callahan married his wife Betty Ann, and the couple spent the summer that followed in El Segundo, California, where Darry worked for Chevron. Returning to Corvallis for his senior year, Callahan served as president of the school's chapter of Tau Beta Pi, an engineering honorary, and was also active in the student chapter of the American Institute of Chemical Engineers. He graduated with a bachelor of science degree in chemical engineering in June 1964.
From there, Callahan began a career at Chevron that would span the next four decades. He began as a research engineer at the Chevron Research Company in Richmond, California, working on refinery plant processes. After six years in process design, Callahan sought out a new challenge and transferred into financial analysis for the company, concentrating on domestic operations. A few years later, Callahan broadened his focus to international work and moved into Chevron's foreign operations staff.
In 1980, Callahan was named president of Chevron Oil Bahamas Limited, his first managerial job. He and his family returned stateside in 1982, where Callahan held a variety of positions in domestic marketing, including manager of pricing and evaluation, manager of commercial and industrial products, and general manager of marketing operations.
In 1987, Callahan assumed the presidency of Warren Petroleum Company, a subsidiary of Chevron. In 1991, he became senior vice president and chief operating officer of Chevron Chemical Company, and was promoted to president and CEO of the company in 1999. The following year, he led the merger of Chevron Chemical with Phillips Chemical Company. In 2000, Callahan was presented with an award for "Outstanding Contribution to the Field of Organizational Behavior Management" by the Organizational Behavior Management Network, a recognition of the reinforcement-based leadership program that he introduced while an executive with Chevron Chemical Company.
In 2001, Callahan completed his term as president of Chevron-Phillips and was named Executive Vice President of Power, Chemicals, and Technology for ChevronTexaco. He also continued to serve on the board of directors for Chevron Phillips Chemical Company. In 2003, he retired from Chevron after a forty year career with the company.
Callahan reestablished his connections with Oregon State University in 1996, when he joined the OSU Foundation's Board of Trustees, a group that he chaired from 2007 to 2009. In 1999, he was also elected to OSU's College of Engineering Academy of Distinguished Engineers and he subsequently joined the College of Engineering's Chemical, Biological, and Environmental Engineering Advisory Board. Callahan was elected to the OSU Engineering Hall of Fame in 2009, and in 2014 he was named vice chairman of the newly created OSU Board of Trustees.