About Laguna Hills
Fossil Reef Park
Fossil Reef Park is 17 million years old – only preserved portion of Fossil Reef in Orange County.
Tropical shell reef associated with fossil rich beach sand.
48 species of marine fossil vertebrates including shark teeth and Desmostylus.
Extending for six miles north-south across the Saddleback Valley is an unusual limestone deposit called the “Pecten Reef “.
The actual extent of this limestone is suggested to be as great as twenty square miles in Orange County and also found on the Palos Verdes Peninsula, San Clemente Island, Santa Catalina Island, and in Santa Barbara and San Luis Obispo Counties. Its maximum thickness appears to be 300 feet.
When Lake Forest was graded in 1972, a very large limestone formation was uncovered. Many Pecten shells were found at the site and thus the name “Pecten Reef” was given by local paleontologists. The exposures represent the ocean floor, as it existed 17 million years ago. The site was destroyed by a housing project after only a limited time of research. A second exposure of reef was discovered in Laguna Hills in 1973.
The Natural History Foundation of Orange County worked with the Orange County Environment Management Agency planning staff and the Affordable Communities land owner to preserve a portion of the reef. The exposed fossil ridge was recognized as a County prehistoric site by the Orange County Historical Commission which dedicated the one acre Fossil Reef Park in Laguna Hills in 1982.
Most of the fossils in the reef are the molds and internal casts of large scallops (Pectens), clams, and snails. The large size of the scallops suggests a tropical environment. The reef is unique, as it is part of the ancient sea floor that has been exposed by tectonic uplift and weathering processes. The uplift took place during the last million years and has formed the Santa Ana Mountains and the San Joaquin Hills. The rigid limestone did not bend during uplift but broke along local faults. A fault extends east-west across the northwest edge of the park and appears to extend in a general direction under the scoreboard on the high school baseball field.
The marine muds, that later covered the limestone, contain plankton fossils, shark teeth, fish bones, marine mammal bones, and seaweed imprints. A large baleen whale was collected between the park and the high school in 1981.
Fossils collected from the reef have been curated by the city and placed on display at the Laguna Hills Community Center.
FOSSIL REEF
“Before you are the white limestone remains of an 18,000,000-year old tropical shell reef. Formed in a shallow bay, it contains fossils of scallops, clams, and tube worms. Mudstones of the same age, found nearby, hold fossil whales and shark teeth. Later, as the Santa Ana Mountains rose, the rigid limestone buckled and broke along small faults. We can now see evidence that tropical seas once covered the spot where you stand.”
Historical Site No. 28
Orange County Board of Supervisors
Orange County Historical Commission
Donated by AFCOM Development
Placed 1952
Fossil Reef Park is located on Via Lomas between Moulton Parkway and Alicia Parkway.
History of Laguna Hills
Laguna Hills is built on one of the major land grants developed during the Rancho Era. Following Mexico’s independence from Spain in 1821, those who had served in the government or who had friends in authority, were given vast lands for cattle grazing. Rancho Lomas de Santiago, Rancho San Joaquin, and Rancho Niguel covered much of the western portion of the Saddleback Valley. Don Juan Avila was granted the 13,000 Rancho Niguel on which Laguna Hills is located.
In 1874, Lewis Moulton purchased Rancho Niguel from Don Juan Avila and increased the original grant to 22,000 acres. Moulton and his partner, Jean Piedra Daguerre, used the ranch to raise sheep and cattle. The Moulton Ranch was eventually subdivided in the early 1960’s, part of which is recognized as Laguna Hills.
Incorporation efforts began in 1987 and on March 5, 1991, the goal of incorporation was finally achieved with 86% of the residents voting in favor of forming the City of Laguna Hills. On December 20, 1991, Laguna Hills officially became a City.
On November 14, 1995, the City Council approved annexation of the North Laguna Hills area, which became part of the incorporated City on July 1, 1996.
On September 18, 2000, with the overwhelming support from the 1,800 residents, the “Westside” Annexation Area officially became part of the incorporated City. The annexation added 149 acres of residential land, which includes the Aliso Viejo Community Association’s Sheep Hills Park.
Civic Center
24035 El Toro Rd.
Laguna Hills, CA 92653 | Map
Phone: (949) 707-2600
Fax: City Manager, Administration, Finance
(949) 707-2614
City Clerk, Community Development, Police Services, Public Services, Engineering
(949) 707-2633
Hours of Operation:
8:00 a.m. – 5:00 p.m., Monday to Friday
Hours for Planning and Building Departments:
1:00 p.m. – 5:30 p.m., Monday to Thursday
1:00 p.m. – 5:00 p.m., Friday
Community Center & Sports Complex
25555 Alicia Pkwy.
Laguna Hills, CA 92653 Map
Phone: Main Line: (949) 707-2680
Class Registration: (949) 707-2680
Facility Information: (949) 707-2686
Field Usage: (949) 707-2687
Sports Leagues: (949) 707-2690
Mud Line: (949) 707-2689
Technology Branch Library: (949) 707-2699
Fax: (949) 707-2688
Hours of Operation:
8:00 a.m. – 10:00 p.m., Monday to Saturday
12:00 noon – 6:00 p.m., Sunday


















