Just before noon yesterday, an earthquake measuring 5.4 on the Richter scale was felt in southern California. The epicenter was in Chino Hills, near the point where Los Angeles, San Bernardino and Orange counties meet. The epicenter was about 40 miles from the far eastern edge of the park and approximately 70 miles from headquarters in Thousand Oaks. While felt throughout the park, no staff injuries have been reported, nor any damage to buildings, dams, reservoirs or other facilities. Damaged buildings are being reported within a 10 to 15 mile circumference of the epicenter, though, and numerous smaller aftershocks have also been felt.