Irvine Ranch Open Space

Irvine Ranch Open Space
13042 Old Myford Rd.
Irvine, CA 92602
(714) 973-6696 

Hours: Access to areas in the Irvine Ranch Open Space, including Black Star Wilderness Park and Fremont, Limestone and Weir canyon nature preserves is available through scheduled programs.

For a full list of activities, please visit

On June 29, 2010 the Orange County Board of Supervisors voted to accept a donation of approximately 20,000 acres from the Irvine Company to the County for preservation and guided recreation.

These special, protected wildlands, known collectively as the Irvine Ranch Open Space, are operated by OC Parks, with public programs and activities available through the Irvine Ranch Conservancy.

Based on the geological and ecological significance, nearly 40,000 acres of open space on the historic Irvine Ranch, including the 20,000 of the Irvine Ranch Open Space, have been designated a Natural Landmark by both the State of California and the U.S. Department of the Interior. This honor recognizes the exceptional value of these lands to California and the entire nation.

Recreation opportunities are available through regularly scheduled programs. These activities include hiking, mountain biking, equestrian rides, naturalist-guided tours and self-guided wilderness access days. Other uses are prohibited by the terms of the deed restrictions, conservation easements, County wilderness park designations, and the Orange County Central Coastal Natural Community Conservation Plan permit.

We invite you to visit and select from the many free activities offered. In addition to a variety of recreational programs, there are opportunities to participate in scientific research, stewardship and other volunteer activities.


June 9, 2016 
Helicopter Conducting Aerial Weed Survey

News ImageBetween June 18 to June 24 and July 5 to July 12, the Nature Communities Coalition (NCC), in collaboration with OC Parks, Irvine Ranch Conservancy, and The Nature Conservancy will conduct an aerial weed survey during daylight hours using a small, low-flying helicopter to document and map the distribution of over 30 weed species located within selected inland parks and open space areas.

Whiting Ranch, Irvine, Santiago Oaks, Irvine Ranch Open Space and Peters Canyon will be included in the survey.

The resulting information will provide details about the abundance and distribution of invasive weeds and help land managers evaluate the effectiveness of current weed monitoring practices, identify emerging weed problems, and strategically plan future weed management actions.

May 6, 2016 
New East Sinks Viewing Deck Opens in Limestone Canyon

News ImageThe new East Sinks Viewing Deck, which boasts stunning vistas of Orange County’s very own “mini Grand Canyon,” is now open for visitors after a ribbon-cutting ceremony May 3 in OC Parks’ Limestone Canyon Nature Preserve. Orange County Supervisor Todd Spitzer and OC Parks staff were joined by hikers, mountain bikers, equestrians, and Irvine Ranch Conservancy staff and volunteers in dedicating the new deck, which is the second platform overlooking The Sinks.

November 18, 2014 
Board of Supervisors Accepts 2,500-Acre Gift

Today the Orange County Board of Supervisors voted to accept 2,500 acres of open space, donated by the Irvine Company to the County for preservation and public recreation. The donation provides additional connectivity to the 20,000 acres the Irvine Company donated to the County in 2010, which marked the largest single donation of land to the County in its history. The land accepted today was previously slated for construction of approximately 5,000 homes.

August 20, 2014 
Explore OC Parks’ Irvine Ranch Open Space

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In 2010, OC Parks accepted a gift or 20,000 acres of open space from the Irvine Company. These special, protected wildlands, known as the Irvine Ranch Open Space, are operated by OC Parks, with public programs and activities available through the Irvine Ranch Conservancy.

August 19, 2016 
OC Parks Mobile App Now Available

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The OC Parks mobile application is now available to download. The new app makes it easy to explore all that the County regional and wilderness parks have to offer.

Using the OC Parks app for iOS or Android, you can easily get outside and find a park near you with the most detailed, accurate maps of all regional, wilderness, beach and historic parks and regional trails operated by the County of Orange. The app also offers detailed park descriptions and photos.

The mobile app lets users easily locate the closest playgrounds, parking and restrooms in each park. Search recent OC Parks news, events and alerts regarding park access, weather, trail conditions and more.

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