Calling the Irvine Ranch Land Reserve (IRLR), “a shining example of our nation’s natural treasures,” National Park Service Director Fran Mainella recently designated 37,000 acres of the IRLR a “National Natural Landmark,” making it the first site in California to receive NNL designation since 1987.
These NNLs -- and there are fewer than 600 of them nationwide -- are awarded by the Interior Department and bestowed upon areas, both public and private, that are recognized as outstanding examples of the country’s natural heritage.
Specifically in the case of Irvine, the areas recognized include:
- Limestone and Fremont canyons, in the northern section of the Irvine Ranch in unincorporated county territory.
- Peters Canyon Regional Park, near the city of Orange and maintained by the County of Orange.
- Crystal Cove State Park and Laguna Coast Wilderness Park, which form a vast, contiguous open space system stretching between the cities of Newport Beach and Laguna Beach and extend inland along Laguna Canyon Road.
- Bommer Canyon, a key part of the city of Irvine’s southern open space preserve.
The Irvine Reserve now represents one of the few places in Southern California where habitats have been preserved that stretch from the mountains to the sea, protecting plants and endangered animals.
To that end, California Gov. Arnold Schwarzenegger, when visiting the reserve, said, “We must leave the state a better place than we found it.”
‘Important, Diverse and Dramatic’
Like Natural Historical Landmarks, an NNL designation is voluntary and does not require designated properties to be owned by public entities -- in fact, more than 30 percent of NNL land is entirely privately owned.
Participation in the NNL Program does not carry any requirements regarding public access, either, but is simply an agreement between the property owner and the federal government “to retain the integrity of their NNL property as it was when designated.”
As for the site at Irvine, AAPG member John Cooper, emeritus professor of geology at California State University, Fullerton, and lead author on the IRLR-PNNL Geology Report, Evaluation of the Irvine Ranch Land Reserve Potential National, says, “I know of no other place where such a compact area contains the record of such an important, diverse and dramatic geologic history -- a fascinating story that lies in the record of the rocks, written in stone.”
Cooper presented the paper “The Irvine Ranch National Natural Landmark, Orange County, California: A Geologic Record That Preserves The Major Tectono-Stratigraphic Events of the Greater Los Angeles Basin Region and a Natural Laboratory for Neotectonic Research,” at the recent AAPG Annual Convention in Long Beach, Calif.
The IRLR is the best of a rare set of places in the South Pacific Border Province where the geologic history of a long time-span (nearly 90 million years), intact and structurally uncompromised stratigraphic record is well preserved, both naturally and through a legacy of sound stewardship that has been sensitive to conservation and protection.”
Another AAPG member and former AAPG Distinguished Lecturer, Richard J. Behl, professor of geological sciences, California State University, Long Beach, and current president of the SEPM Pacific Section, agrees:
“It would be hard to overemphasize the importance of the Irvine Ranch National Natural Landmark’s value for science and education,” Behl said.
Calling Irvine a “world-class geological field” because of its potential for scientific research, Behl noted that the “landscape contains large swaths of coastal sage scrub, a rare habitat found only in coastal southern California and northern Baja California. The combination of unusual geological and rare biological characteristics is what gives these parts of the Reserve such scientific value.
“I do not think that there is another NNL site in all of the United States,” he said, “that places such a wealth of geologic features as close to such a major population center.”
A Million Reasons Why
And that center, of course, is Los Angeles.
Behl says that the more America becomes urbanized, the more “removed” people are from the natural environment and it is places like Irvine Ranch Land Reserve that brings them close, literally, to nature.
“Designation of the IRLR ... will greatly enhance the public understanding of earth history and the geologic record of where they live,” he added.
Cooper, too, believes that the NNL designation will draw attention to the scientific and educational importance of the region and help people “to better understand and appreciate the culture of conservation and preservation.”
Specifically, the site at Irvine is populated with:
- High-quality exposures of both continental and marine sedimentary deposits that record the history of the North American margin since the late Mesozoic.
- Different tectonic settings and provenances and contain important vertebrate fossils.
- Marine deposits of a larger number of depositional and tectonic settings.
- Paleontologic records, including superior assemblages of vertebrate and invertebrate fossils.
- Igneous deposits that include intrusives and extrusives associated with Jurassic-Cretaceous subduction.
“This is a rare combination of fascinating and important geologic features for one limited area,” Behl said.
While he thinks the national designation is beneficial to future study, he hopes the “designation does not end up placing an additional layer of bureaucracy over the area.
“However, the culmination of the transfer of land out of private hands (where there are liability concerns or fear that scientists may discover something that may interfere with the development potential of the land) to the public will be and already is beneficial,” he said. “I think that it will provide a stronger context for many kinds of plans and proposals from pure scientific research to educational programs.
“There were many important geologic locations in private ownership that became inaccessible because of litigation and regulatory concerns until consensus plans were developed,” he added.
These designations may, though, be more of a psychological and philosophical boost than a practical and educational one.
“I am not really sure,” Behl said, “what the concrete benefit of the NNL designation will be other than in uniting the entire community with a shared understanding and commitment to preserve, cherish, study and understand these lands that are still wild, yet so close to literally tens of millions of people.”