Rancho La Brea Tar Pit (image) University of California - Riverside Caption Active fossil excavation site, Pit 91, located at the Rancho La Brea tar pits, Los Angeles, Calif. Pit 91 has yielded thousands of animal fossils. Credit D. E. Crowley, UCR. Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.