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Nathan Gregory, Ph.D.

Senior Vice President & Chief Programs Officer

Nathan Gregory, Ph.D.

​Nathan oversees all of the program areas at the Irvine Ranch Conservancy.

Early in his career, Nathan worked on invasive species control and wildlife conservation and management issues in Hawaii, Alaska, and Colorado, and he later earned his Ph.D. in Ecology and Evolutionary Biology from Princeton University, where he studied the effects of land use on bird communities in Kenya. He then worked as a research ecologist and project manager for the non-profit Institute for Wildlife Studies (IWS) focusing on the conservation of the desert tortoise in the Mojave Desert and the San Clemente Island fox. After leaving IWS, Nathan served for two years as an AAAS Science and Technology Policy Fellow at the United States Agency for International Development. During his time in Washington and prior to joining the Conservancy in 2016, Nathan worked on biodiversity conservation and international development issues in multiple countries.

Senior Leadership Team

Michael O'Connell

Michael O’Connell

President & Chief Executive Officer
Sherry Fuller

Sherry Fuller

Senior Director, Human Resources Management
Adam Maywhort

Adam Maywhort

Director, Planning & Infrastructure
Dave Raetz

Dave Raetz

Vice President & Chief Administration Officer

Board of Directors

Irvine Ranch Conservancy is a California non-profit organization.

It was founded in 2005 to help care for the tens of thousands of open space acres preserved in public ownership on the historic Irvine Ranch. The Conservancy works with landowners such as OC Parks, City of Irvine and City of Newport Beach to preserve and restore these lands and help people enjoy them. The Conservancy has an independent board of directors overseeing its strategy and operations.


Geoff Barnard
Retired Senior VP, The Nature Conservancy;
Former President, Grand Canyon Trust;
Consultant in non-profit strategy and management

Vice Chair
Ann Muscat, Ph.D.
Retired President and CEO,
Catalina Island Conservancy

Dave Doran, CPA
Retired Managing Partner
​White Nelson Diehl Evans LLP,
Member of AICPA, CSCPA

Nikki Buffa
Counsel, Latham & Watkins, LLP
Former Deputy Chief of Staff,
US Department of Interior

Assistant Secretary
Ken Kramer
Retired Superintendent,
​Orange Coast District, CA State Parks

Past Chairman
Albert F. Bennett, Ph.D.
Dean Emeritus, School of Biological Sciences,
University of California Irvine

Michael O’Connell
CEO, Irvine Ranch Conservancy


Patrick Bradley
President, Southern Pacific Region,
Whole Foods Market

Bill Campbell
OC Businessman, Former County Supervisor, and Former State Assemblyman

Jane Russo
Retired Superintendent,
Santa Ana School District

Sharon Farrell
Executive Vice President of Programs, Stewardship, and Science,
Golden Gate National Parks Conservancy

David Szymanski
Superintendent, Santa Monica Mountains National Recreation Area,
US National Park Service

Contact Us

Looking for another member of our team? Visit our contact page for a full list of Irvine Ranch Conservancy departments and staff.

To contact members of the Board of Directors, please call the Administrative Specialist at 714-508-4756 or email