This project has inventoried and produced a digital database of Late Miocene through Holocene micropaleontologic slides and data available in the USGS collections along the lower Colorado River corridor, Imperial Valley, and Gulf of California. The digital database includes the location of samples, content of the samples, results of analyses, and other information in a format that can be readily searched in the future by researchers, micropaleontologists, and geologists as well as land managers and tribes. These materials are of particular importance in understanding the development of the Gulf of California, Imperial Valley, and Colorado River, during this time as an analog for predicting future conditions and land use.