A Legacy Built on Principle
The story of Wanger Jones Helsley PC begins with Judge Oliver W. Wanger — a founding force whose values continue to guide the firm today.
Oliver W. Wanger
Emeritus
Oliver Winston Wanger was a founding force behind the principles that continue to guide Wanger Jones Helsley PC: integrity, discipline, and an unwavering commitment to the rule of law. His career reflected a rare combination of public service, legal scholarship, and leadership that shaped the legal landscape of California's Central Valley and beyond.
After serving as a sergeant in the United States Marine Corps Reserve, Judge Wanger began his legal career as a deputy district attorney in Fresno County. He later served as City Attorney for the City of Mendota and co-founded the San Joaquin College of Law, where he also served as professor and dean, helping to educate and mentor generations of attorneys.
In 1991, Judge Wanger was appointed to the United States District Court for the Eastern District of California, where he served with distinction for more than two decades until 2011. As a federal judge, he presided over complex and consequential cases, including the landmark water and environmental matters central to the region.
Judge Wanger's legacy as a founder rests not only in his professional accomplishments but in the values he instilled: rigor, fairness, and service to community. He presided over more than 600 jury trials to verdict across his career. Those values remain central to how Wanger Jones Helsley serves its clients today.
Core Pillars of Service
- U.S. Marine Corps Veteran
- U.S. District Court Judge
- Law School Co-Founder
- Central Valley Visionary
From the Marine Corps to the Federal Bench
- Early Career
Sergeant, U.S. Marine Corps Reserve
Service before practice — a discipline that would define his approach to the law.
- Fresno County
Deputy District Attorney
Began his legal career prosecuting cases on behalf of the people of Fresno County.
- City of Mendota
City Attorney
Served as City Attorney for Mendota, earning a reputation for thoughtful counsel and principled advocacy.
- Co-Founder
San Joaquin College of Law
Helped found the school and served as professor and dean, mentoring generations of Central Valley attorneys.
- 1991
U.S. District Court Judge
Appointed to the United States District Court for the Eastern District of California, where he served with distinction for more than two decades.
The Foundation of Our Practice
Judge Wanger's influence is most visible not in any single matter, but in the principles our attorneys carry into every engagement.
Integrity
An uncompromising standard in every matter, large or small.
Discipline
Rigor and preparation are the foundation of effective advocacy.
Rule of Law
An unwavering commitment to the institutions that protect our clients.
Service
Mentorship, education, and community remain central to who we are.
Rigor, fairness, and service to community. Those values remain central to the mission of Wanger Jones Helsley PC.
The Legacy Continues
The principles Hon. Oliver W. Wanger established still shape Wanger Jones Helsley today. Meet the attorneys carrying that work forward across the firm's nine practice specialties, or review the matters that demonstrate how the firm applies trial-tested judgment to its clients' most consequential challenges.