Karen Mitchoff
Five Decades of Fearless Public Service
"You are entitled to your own opinion but not your own set of facts."
Five Decades of Fearless Public Service
"You are entitled to your own opinion but not your own set of facts."
From a confident 17-year-old legal secretary in Martinez to Board Chair of Contra Costa County, Karen Mitchoff's career was marked by seizing every opportunity, fearless advocacy, and an unwavering commitment to facts over opinions. Her story is one of extraordinary dedication—beginning in 1981 in the Sheriff's office and spanning five decades of transformative public service across special districts, city government, and county leadership.
At just 17 years old, Karen began her public service career as Executive Secretary to Sheriff-Coroner Richard Rainey in Martinez. This was her entry into Contra Costa County government—a relationship that would last 50 years. She was mentored by legal secretary Pat Calkins and promoted to paralegal by attorney Kent Brewer, learning the fundamentals of legal procedures and public service that would shape her entire career.
After a brief stint in private practice, Karen recognized the pull of public service and returned to county government as Chief of Staff to Supervisors Sunne Wright McPeak and Mark DeSaulnier (1987-1998). Over 11 transformative years, she learned the intricacies of county leadership, regional collaboration, and constituent services. This behind-the-scenes apprenticeship gave her unparalleled insight into how county government works—expertise she would later apply as a supervisor herself.
Karen transitioned to the role of Fiscal and Administrative Analyst for Contra Costa Employment and Human Services Department (1998-2010), deepening her expertise in budget management, program evaluation, and data-driven policy. This 12-year period honed her analytical skills and commitment to evidence-based decision-making—principles that would become hallmarks of her leadership style. She completed her Bachelor of Arts in Human Development from CSU East Bay in 2000 while working full-time.
Karen's elected service began with her appointment to the Pleasant Hill Recreation and Park District Board in 2003. She was elected to the board in 2004 and 2006, serving as Board Chair in 2005 and 2006. This role demonstrated her commitment to quality of life issues and community development—values that would define her entire career.
Elected to the Pleasant Hill City Council in 2008 as the top vote-getter, Karen served as Mayor in 2010. During her time as mayor, she navigated the city through economic challenges while maintaining Pleasant Hill's AA bond rating—one of only a handful of cities nationwide to achieve an upgrade during that period. She championed fiscal responsibility and smart growth.
In January 2011, Karen was sworn in as Contra Costa County District IV Supervisor, representing Pleasant Hill and significant portions of Walnut Creek and Concord. Over three terms (12 years), she became known for cutting through bureaucracy, championing data-driven decisions, and fighting for her constituents' needs—from transportation improvements to environmental protection to public safety.
In her final year of service, Karen was elected Board Chair—the culmination of her public service career. She led the county through continued pandemic recovery, championed Measure X funding priorities including mental health crisis response (A3 program), violence prevention initiatives, and community safety programs. Her leadership emphasized collaboration, transparency, and evidence-based policy.
Karen's retirement from the Board of Supervisors didn't mean retirement from public service. She became Chairperson of the Bay Area Air Quality Management District (BAAQMD) Board, continuing her environmental advocacy. After seven months of retirement, she announced her candidacy for California State Assembly District 15 (July 2023), earning the Mercury News endorsement as "the best pick in a weak group of Assembly candidates." Though she did not win the March 2024 primary, her campaign demonstrated an unwavering commitment to addressing state-level issues that matter to communities—proving that five decades of public service had only strengthened her dedication to making a difference.
Karen worked tirelessly on major transportation improvements including additional lanes on Highway 4, completion of the Caldecott Tunnel's fourth bore ($5M under budget), and the Highway 4/Interstate-680 interchange improvements—projects that directly improved daily commutes for thousands. She championed GoMentum Station on the former Concord Naval Weapons Station, bringing autonomous vehicle testing companies to the region and positioning Contra Costa as the nation's largest secure testing facility for transportation technology. During her Pleasant Hill tenure, she secured the $11M Buskirk Avenue straightening project, eliminating a dangerous curve.
Under Karen's advocacy, Buchanan Field Airport expanded its offerings with JetSuiteX commercial flights out of Concord and became home to a growing drone industry with offices and testing facilities. She secured federal funding for a new terminal and flight tower, ensuring the airport would serve the community for generations while carefully balancing economic growth with neighborhood impacts. Her vision transformed the airport into a regional economic hub.
Karen's passion for reading translated into passionate advocacy for libraries. She played a pivotal role in the partnership that enabled Pleasant Hill's new $27 million library building to be completed, working across jurisdictions to fund and realize this community asset. In 2022, she established a revocable trust fund for the Contra Costa County Library system, ensuring her commitment to literacy would continue beyond her tenure. Her advocacy helped expand library services countywide.
Karen championed Measure X, a half-cent sales tax approved by voters in November 2020, generating approximately $81 million annually for essential services. She helped create the groundbreaking A3 (Anyone, Anytime, Anywhere) mobile crisis teams—behavioral health professionals responding to mental health emergencies instead of police. The measure funded violence prevention programs, $12 million annually for affordable housing, and secured $75 million for new county medical center facilities. This innovative approach to mental health crisis response became a national model.
As the county's representative to the Delta Counties Coalition, Karen was a fierce advocate for protecting the Sacramento-San Joaquin Delta ecosystem while ensuring reliable water supplies for millions of Californians. She championed science-based environmental policies, fought against poorly planned water diversion projects, and worked to balance agricultural, urban, and ecological needs. Her appointment as Chairperson of the Bay Area Air Quality Management District Board (2022) extended her environmental leadership to regional air quality protection.
During the COVID-19 pandemic, Karen provided steady, science-based leadership as the county navigated unprecedented public health challenges. She championed fact-based decision-making, supported the Health Services Department's evidence-driven approach, and fought against misinformation. Her leadership helped the county balance public safety with economic recovery, ensured equitable vaccine distribution, and maintained essential services during crisis. Colleagues praised her "fearless commitment to truth, science, and leadership against misinformation."
Karen was a passionate advocate for older adults, leading development of the county's Master Plan for Aging and championing aging-in-place campus initiatives. She worked to expand senior services, improve accessibility, and ensure quality of life for Contra Costa's aging population. Her advocacy secured millions in funding for senior centers, meal programs, and support services. As Debbie Toth, CEO of Choice in Aging, noted: "Your lifting up of older adults, your investment in time, policy, energy and effort has been unparalleled. Your leadership has saved lives."
In December 2022, the Contra Costa County Board Chambers were officially renamed in Karen Mitchoff's honor—the county's highest tribute to her 50 years of public service. The county administration building was bathed in purple light during the dedication ceremony, symbolizing the lasting impact of her leadership. This unprecedented recognition acknowledged not just her 12 years as supervisor, but her entire career of service from legal secretary to Board Chair. She is believed to be the only supervisor who served in elected office at three levels: special district, city council, and county board.
"Through her years in public service, Mitchoff has built a reputation as a no-nonsense, highly effective, focused and sometimes sharp-spoken leader. Your leadership, your lifting up of older adults, your investment in time, policy, energy and effort has been unparalleled. Your leadership has saved lives."
Karen Mitchoff's approach to public service was defined by several core principles that she lived by throughout her 50-year career:
Karen's contributions to Contra Costa County and the Bay Area have been widely recognized:
Bachelor of Arts in Human Development
California State University, East Bay (completed 2000 while working full-time)
Associate of Arts in Business
Diablo Valley College
In her farewell remarks to the Board of Supervisors in December 2022, Karen reflected on 50 years of service with gratitude and a warning. She thanked the mentors, colleagues, and staff who supported her journey, but also issued a frank challenge to the public: civility and factual discourse matter. She expressed concern about the vitriol directed at public servants, noting it discourages qualified people from running for office. "You know where Karen stands," people said—and they were right. Her legacy is one of transparency, accountability, fearless advocacy, and getting things done.
From recreation and parks to city council to county supervisor to air quality leadership, Karen Mitchoff's career exemplifies what dedicated public service looks like. She leaves behind transformed transportation systems, safer communities, stronger environmental protections, better libraries, and a generation of public servants inspired by her example. As Supervisor Diane Burgis noted, "You have made me a better leader."
Karen's story proves that public service is not just about holding office—it's about seizing opportunities, speaking truth, demanding evidence, and always, always putting the community first.