The Coast Miwok are the only known Native American tribal group to occupy all of Marin and Southern Sonoma Counties. Obsidian hydration has dated their occupation back several millennia. A collection of worked obsidian, bone, stone mortars and tools, and shell are now held in the museum with faunal remains and debitage. These materials were excavated by archeologists from San Francisco Bay Area universities in the 1960s-1980s in cooperation with the National Park Service on lands within the park boundaries. Unique coastal materials used to make tools and ornaments include whale bone, abalone, clam and olivella shells. Studies indicate significant prehistoric manufacturing sites existed on the Peninsula where beads and ornaments were made from these materials.
A larger type sample of individual items from a number of excavated sites is available on the National Park Service web catalog site where catalog records with images are posted. Use search term Coast Miwok.