The hook
A slab of limestone in the Sierra foothills is dimpled with 1,185 grinding holes, the most of any bedrock mortar site in North America, worn there by the Miwok over thousands of years.
01Why it's worth it
The Miwok ground acorns into meal here for so many generations that they left 1,185 mortar cups in one outcrop of marbleized limestone, the largest such collection anywhere on the continent, alongside 363 petroglyphs carved two to three thousand years ago. The park is built around that rock, but it's more than an artifact. A Miwok village has been reconstructed in the meadow, with bark houses and a large ceremonial roundhouse that local tribes still use for dances and Big Time gatherings each year, so it reads as a living place rather than a ruin. That's a rare thing among California's Native sites, most of which were erased. A regional museum fills in the culture, and oak-woodland trails loop the small valley.
02How to experience it
It's near Pine Grove in Amador County, about two and a half hours from the Bay, with a day-use fee. The grinding rock and village are a short walk from the lot; go quietly, and don't walk on the rock itself. It pairs naturally with Black Chasm cave and the gold-rush town of Volcano, both minutes away.