Giant Fossils Trove Found in California Declared One of the Most Significant in State History On 5/24/21 at 12:44 PM EDT A petrified forest discovered by a ranger for California's East Bay Municipal Utility District (EBMUD) has yielded what SFGate calls the "the largest and most diverse" collection of fossils in the state's history. Geologists and paleontologists at California State University, Chico, which has partnered with the district to excavate, identify, preserve and store the fossils, anticipate that conducting a complete inventory could take years. But they're thrilled at the prospect of building on existing knowledge of prehistoric North America. While walking last July through the Mokelumne River watershed, a drainage basin in the Sierra Nevada foothills that provides water to 1.4 million Bay Area residents, Greg Francek noticed a petrified tree protruding from the mud. Looking around, he noticed another, and then another, and then another.