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Irvine Ranch Conservancy Celebrates the 50th Anniversary of Earth Day and the History of Irvine Ranch

​ April 22nd is the 50th anniversary of Earth Day, which commemorates the unified response to an environment in crisis and the beginning of an environmental movement. For Irvine Ranch Conservancy, Earth Day has special meaning, marking the anniversaries of the City of Irvine’s Open Space Initiative and the designation as the first-ever California Natural Landmark.
What we know today as the Irvine Ranch Natural Landmarks was once one of California’s earliest and most productive large-scale agricultural enterprises. Under the leadership of James Irvine Jr., the land known as the Irvine Ranch produced a variety of crops including beans, oranges, barley, cauliflower, grapes, papayas and more. A portion of the land was also home to the Bommer Canyon Cattle Camp and housed hundreds of head of cattle from the late 1800s until 2001. You can still find some of the original structures on the land to this day!
​In the early 1960s, the family of James Irvine began developing a master plan for the Irvine Ranch land, partly to counter the wave of unplanned development in the region after World War II. After nearly a decade, the family completed their master plan, which contained only ten percent of open space and 90 percent development. When the company was sold in 1979, the amount of open space was increased to contain more than 50 percent once the master plan was finalized in 2004.
Thanks to the efforts of local citizens, the percentage of land development was decreased through actions such as the passing of the Irvine Open Space Initiative on Earth Day in 1988. Additionally, the Irvine Company and its Chairman Donald Bren recognized the critical value of including more open space in the master plan. Another major factor was the development of a conservation plan under the Endangered Species Act called the Natural Community Conservation Plan, which identified and provides for the regional protection of plants, animals, and their habitats, while allowing compatible and appropriate economic activity. Today, all the open space lands are publicly owned.
Then in 2006, nearly 40,000 acres of open space was designated a National Natural Landmark by the US National Park Service, and the state of California designated the same lands as the first California Natural Landmark on Earth Day in 2008. Both designations required exhaustive, independent peer-reviewed scientific evaluation by a team of academic scientists. Although there are more than 600 designated National Natural Landmarks in the U.S., the Irvine Ranch is the only place to receive this honor for both its biology and geology.
“Most of the critical history of the Irvine Ranch open space lands has been written since the first Earth Day in 1970,” said Irvine Ranch Conservancy President and CEO, Michael O’Connell. “Turning a historic ranch into a world-class nature preserve is a complicated undertaking. A community of caring people and organizations has come together on the lands, including more than 500 dedicated, highly-trained volunteers who contribute an average of 44,000 hours every year, as well as more than 30,000 people who participate and enjoy free public programs and activities offered by the volunteers.”
Irvine Ranch Conservancy and our partners OC Parks, the City of Irvine and the City of Newport Beach, along with a community of stewards have been diligently transforming the former ranch land into thousands of acres of natural habitat, where native species can thrive and nature lovers can safely explore. Over the years, our team has converted old dirt ranch roads into trails that provide high quality visitor experiences, constructed trailheads and staging areas, along with interpretive signage and facilities. In addition, IRC’s natural resource management team continues to focus on the restoration of old grazing and pasture lands back to native habitats, while increasing connectedness of the entire landscape.
“Because our mission is to protect, restore and enhance the natural resources of the Irvine Ranch Natural Landmarks forever and help people enjoy them, at IRC every day is Earth Day,” said O’Connell. “But April 22 is special, because it is an annual reminder to us and the people who love these lands why it is so important that we care for them now and for future generations.”
Looking toward the future, Irvine Ranch Conservancy will continue its mission to restore more than 5,000 acres of native habitat, maintain the highest quality system of trails and facilities, and continue to grow a community of active, engaged supporters for the stewardship of the Irvine Ranch Natural Landmarks.
“We want to leave the land in better shape than we found it for our children’s children and the planet,” says O’Connell. “I had the special experience of celebrating the 20th anniversary of Earth Day in 1990 on the National Mall in Washington, DC with more than 500,000 other people. It is amazing to think that the spectacular conservation achievements on the Irvine Ranch Natural Landmarks were just getting started then, and how far we’ve come in the last 30 years. Especially now, we are being reminded every day of the importance of nature and open spaces in our lives. That, more than anything, is what Earth Day is about.”
Continue to celebrate Earth Day with Irvine Ranch Conservancy’s Butterfly Social Media Takeover happening April 27-May 1! Each day, IRC will highlight three beautiful butterflies that call Orange County home on Instagram, Facebook and Twitter. Join the virtual butterfly takeover by “liking” the Landmarks’ Facebook page (, following on Twitter (@IRLandmarks), and following on Instagram (@OCMountainstoSea).
To learn more about Irvine Ranch Conservancy and the Irvine Ranch Natural Landmarks visit