Indian Grinding Rock

When you finally encounter the arresting Indian Grinding Rock as you make your way through the historic park’s South Nature trail, it isn’t difficult to conjure a clear image of the activities that gave the bedrock its name. A visually impressive 173 feet long and dotted with over 1,000 mortar cups, it was the site where Milwok villagers once worked tirelessly to make corn meal by grinding acorns into flour with stone tools.