Perimeter Trail

Located in the northwest corner of Orange County on the Buena Park/Fullerton border, this park owes its origin to our fascination with fossils. It seems twelve thousand years or so ago, the ring-tailed cat, ground sloth, and ancient mammoth roamed a region of meadows, marshes and woodlands, an environment altogether different from present-day Orange County.

Extensive fossil beds were discovered when sand and gravel was excavated during the 1950s and 60s for construction of the Santa Ana and Riverside freeways by the California Division of Highways (now Caltrans). Paleontologists identified the remains of prehistoric whales, bison and even a camel. By public demand, Emery Borrow Pit, as the excavation site was known, was purchased by Orange County in 1974, opened as Los Coyotes Regional Park in 1981, and later renamed for Ralph B. Clark, a county supervisor.

Exhibits in the park interpretive center tell the intriguing tale of prehistoric Orange County. The discovery of turtles, tapirs, turkeys and an unusual number of vertebrates prompted some researchers to mention the site in the same breath with the legendary La Brea Tar Pits. Other exhibits suggest what the OC was like from way, way back in time—the Pleistocene period of 100,000 years ago and the Late Cretaceous period of 75 million years ago.