This expansive park sits at the south end of the Laguna Greenbelt. Its canyons harbor a pastoral feel unmatched in Orange County. Aliso & Wood Canyons are natural wonders still to be enjoyed.

In this, Orange County’s largest park, the wilderness setting offers a rare opportunity to experience nature in its entire splendor throughout the year. Open for both day use and camping, visitors can enjoy a number of recreational activities, including several unique interpretive programs to acquaint them with the natural splendor of the area.

Lush, sycamore-shaded canyons and high ridges offering views of the Pacific Ocean create a spectacular environment for hiking, mountain biking and horseback riding. Designed to preserve the delicate balance of the natural habitat, a major portion of the park’s 6,500acres is open for use on a limited basis.

As a wildlife sanctuary, Thomas F. Riley Wilderness Park is home to an abundant number of native plants and animal life. Old groves of Western Sycamores and Coast Live Oaks border the park's two seasonally flowing creeks. The remaining land features rolling hills and canyons of Coastal Sage Scrub and grasslands.

Highlighted by carefully restored and maintained natural wetlands, this unique park is bounded by the Santa Ana River and the Costa Mesa Bluffs. Park visitors will find a variety of hiking and interpretive trails, as well as an informal picnic area, all situated within an “ecological staircase” of a salt marsh, fresh-water wetlands, grasslands and woodlands. There is no parking available at Talbert Nature Preserve. Local Costa Mesa city park provide parking. Fairview Park on Placentia Avenue or Vista Park on Victoria Place.

Approximately 4,000 acres of deeply forested canyons, scenic rock formations and grassy rolling hills are enriched by intermittent streams and trails to create an ideal open air opportunity for hikers, mountain bikers and equestrians. The park’s interpretive center features a trail rest stop, cultural and natural history exhibits and park information.