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The primary goal for the second year of this three year ACS-PRF grant was to collect a long sediment core from Lake Elsinore. The core location was determined by seismic reflection data collected during year one of this ACS-PRF grant. Our coring site was located at the lake’s sedimentological depocenter, thus ensuring the most complete and undisturbed sediment package. Over 3 days in June 2010, we acquired a 21 meter sediment core beginning 9 meters below the sediment-water interface and ending 31 meters below the sediment-water interface. The upper 10 meters were collected in 2003 and were not re-cored. We recovered 90% useable sediment – an excellent recovery percentage for scientific research. Initial radiocarbon dates indicate that the 2010 core overlaps with the 2003 core thus guaranteeing a continuous sediment record. One centimeter contiguous sedimentological analyses reveal a variety of sediment types previously unrecognized in the 2003 Holocene (past 10,000 years) sediment core. Most striking is a thick (~6m) laminated-to-semi-laminated, organic rich mud. This organic-rich sediment unit is interpreted to represent a deep lake, perhaps coeval to the Last Glacial Maximum in Southern California. Pending radiocarbon dates from throughout the core will verify the units timing in the upcoming months. Another interesting sediment unit is a ~2m silty sand found 24 meters below the sediment-water interface. Sand at the bottom of lake is unusual, especially in thick, continuous packages. Interpretations for this unit range from a very wet climate (i.e. vigorous run-off), permanent lake environment to a dry climate, shallow lake environment. Over the next several years, detailed physical, chemical, and biological sediment analyses will reveal the best interpretation for the units described above and the many other interesting sediments from the 2010 core. Most importantly, this new sediment core represents the first, high-resolution, continuous, terrestrial paleoclimate record for Southern California that covers the climatically tumultuous early-Holocene to late Glacial transition and the highly variable Last Glacial. Results will be compared to nearby marine paleoclimate records with the objective to evaluate the land-sea climate connection in Southern California. Understanding past relationships/linkages between land-sea climate is important to understanding the modern climate system as sea surface temperatures change in response to climate warming. Initial results will be presented in Fall 2010 at the American Geophysical Union Meeting in San Francisco.