found: Work cat.: Geology of Orange County, California, and the Irvine Ranch National Natural Landmark, c2008:p. viii (On Oct. 6, 2006, the Secretary of the Interior designated a 36,398-acre area within Orange County, Calif., as the Irvine Ranch National Natural Landmark) p. 1 (located in eastern Orange County at the southern end of the greater Los Angeles physiographic basin; northern part of the Peninsular Ranges Province)
found: The Irvine Ranch National Natural Landmark, via the Irvine Company website, Mar. 4, 2009:p. 2 (50,000 acres of public and private land representing half the historic Irvine Ranch have been preserved as the Irvine Ranch Land Reserve; approx. 37,000 of the Reserve has been singled out for its value to the entire nation through federal designation as a National Natural Landmark)
found: National Natural Landmarks Program website, Mar. 4, 2009:National Natural Landmarks Guide (by state) > California > Irvine Ranch (Irvine Ranch National Natural Landmark; designation date: 2006)
notfound: GNIS, Mar. 4, 2009
