Paleobotany enthusiasts (under the auspices of the University California Museum of Paleontology) collect fossil leaves at the Mehrten Formation leaf-yielding locality several miles east of Grass Valley/Nevada City--they are contiguous communities that lie about 85 miles north of Angels Camp (turnoff point for the High Sierra Nevada Disaster Peak Formation fossil plant-bearing area)--northern Mother Lode country. The paleobotanic bonanza occurs along a cliff face, originally exposed by hydraulic gold miners in the mid 1850s. A gold nugget from this area, by the way, weighed in at 11.6 pounds, making it the 22nd heaviest gold nugget ever discovered in California. Photograph taken on October 16, 1993.

32 species of early-late Miocene plants have been identified from this early-late Mehrten Formation locality (9.5 million years old) east of Nevada City/Grass Valley, including: Port orford cedar (not really a cedar, of course, but rather a cypress); Coast redwood; Boxelder maple; an extinct species of Mahonia (barberry); oval-leaved viburnum; Pacific madrone; manzanita; Sierra laurel; Blue oak; Valley oak; California black oak; Oracle oak; an extinct oak similar to the extant Chinese evergreen oak; Oriental white oak; Interior live oak; American sweetgum; Ohio buckeye; Eastern black walnut; Red bay; California bay; roundleaf greenbrier; Western sycamore; Alabama supplejack; Buckbrush; mountain hawthorn; Hollyleaf cherry; Black cottonwood; Quaking aspen; Fremont cottonwood; Shining willow; Mexican buckeye; American elm; an extinct species of grapevine.