Indian Grinding Rock State Historic Park in California’s Sierra Nevada foothills preserves Chaw’se, a marbleized limestone outcrop known to the Miwok as “grinding rock.” The site contains about 1,185 bedrock mortar holes, the largest concentration in North America, created as Miwok people ground acorns and other seeds into meal. Chaw’se also bears petroglyphs, some believed to be two or three thousand years old, and is one of the only known places in California where mortar pits were intentionally decorated. Established in 1962, the park also includes the Chaw’se Regional Indian Museum and a reconstructed Miwok village, making it an important center for preserving Native history.