Irvine Ranch Open Space

Irvine Ranch Open Space 

Eastern Foothills of Orange County. Access through scheduled events only.

Phone: 714-973-6696


Acres: 22,500

Printable Map

Park Hours: Access only through scheduled programs or Wilderness Access Days.

Black Star Canyon Road is always open for public use and access to Cleveland National Forest.

Parking: Free

Dogs: Not permitted, except on Black Star Canyon Road.

Activities and Programs

The Irvine Ranch Open Space consists of protected wildlands, including six nature preserves. OC Parks stewards these special lands in close coordination with the Irvine Ranch Conservancy as land management contractor and The Nature Conservancy, a conservation organization. Various educational and recreational opportunities are available through regularly scheduled programs. Other uses are prohibited as specified by deed restrictions and conservation easements. We invite you to visit and select from the many free activities offered.

Trails: hiking, biking and equestrian activities through regularly scheduled programs

Monthly self-guided Wilderness Access Days scheduled

Named a State and a National Natural Landmark

Volunteer opportunities


On June 29, 2010, the Orange County Board of Supervisors voted to accept a donation of 20,000 acres from the Irvine Company to the County for preservation and guided recreation. Additional acreage was donated in late 2014. The historic Irvine Ranch’s origins date back to the 1830s as a Mexican Land Grant to Don Jose Andres Sepulveda. In 1876, James Irvine bought out his partners on the land. During this time, he successfully fought to secure the borders from squatters and the Southern Pacific Railroad. From 1876 to 2010, the historic Irvine Ranch was used for ranching and mining operations, and evidence of this can still be observed. Based on evaluations and the recommendations of the Science Advisory Committee of the National Park Service, the National Park Service Advisory Board, and the National Park Service director, the Secretary of the Interior designated the Irvine Ranch National Natural Landmark in 2006. A similar objective review led to the designation as a California Natural Landmark on Earth Day 2008 by the California State Parks director.


May 1, 2020 
OC Parks COVID-19 Modified Operations

UPDATED 5/5/21: In an effort to minimize the impacts of coronavirus (COVID-19) on park patrons, staff, and the Orange County community at large, and consistent with the guidance provided by the Centers for Disease Control and Prevention (CDC), Governor’s office, the Orange County Board of Supervisors and the Orange County Health Care Agency (HCA), OC Parks are operating in the following manner.

March 8, 2021 
Extended Spring-Summer Park Hours Begin March 14

The clocks spring forward early March 14, marking the beginning of daylight-saving time and OC Parks’ spring-summer operating schedule.

Spring-summer hours for most regional parks are 7 a.m. to 9 p.m. Wilderness parks and some regional parks are open at 7 a.m. and close at sunset year round.

June 16, 2020 
Information Regarding Unauthorized Trails

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OC Parks serves as the steward of 60,000 acres of County parks, beaches and open space. This stewardship involves the protection and preservation of sustainable, healthy habitat both for generations of future visitors and also the local wildlife that live in it.

The County’s regional and wilderness parks and open space offer hundreds of miles of existing trails for pedestrian, bicycle and equestrian uses. Building and use of unauthorized trails, however, remains an ongoing issue.

These unauthorized trails cut through preserved habitat and jeopardize public access, native habitat and wildlife. In many parks, OC Parks does not even have the discretion to allow or disregard unauthorized trails; it is bound by state and federal agencies to preserve the land.

Here are some of the top reasons to stay off unauthorized, unmarked trails.

September 21, 2018 
Electric Bicycles Now Permitted on Regional Bikeways

For the past 20 years, Orange County Codified Ordinance OCCO 2-5-29(n) prohibited the use of all motorized conveyances, including electric bicycles (eBikes) on all County bikeways and trails.

On July 17, 2018, the Board of Supervisors passed a revision to the ordinance, making the following exception: “Class 1 and Class 2 electric bicycles, as defined by the California Vehicle Code, on those regional paved, off-road bikeways designated for such use by the Director of OC Parks.”

Currently, this means that Class 1 and 2 eBikes are now permitted on more than 75 miles of paved Orange County regional bikeways. Due to safety concerns, all classes of eBikes continue to be prohibited on unpaved trails within regional and wilderness parks.

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