Indian Grinding Rock State Park
Museum and Bedrock Mortar Site
(Amador County)

The park is located at 14881 Pine Grove-Volcano Road in the town of Pine Grove in the Sierra Foothills. It is best to phone them at (209) 296-7488, or go to their website for information on fees and hours. The park is the site of an ancient village of the Sierra Miwok. There are more than 1,000 bedrock mortars here on a large limestone slab just a short walk from a museum at the main parking lot. Some of the mortars are decorated with petroglyphs, and nearby there are reconstructed dwelling huts and a ceremonial lodge that is also known as a roundhouse. Inside the museum there are several interpretive exhibits and artifact displays, as well as a gift shop and book store.

 

Photographs from the Indian Grinding Rock Museum and Grounds

These pictures show some of the more than 1,100 mortar holes present at the main slab in back of the Visitor Center. This is said to be the largest assemblage of bedrock mortars in North America. The far right photo of the uppermost panel clearly shows a petroglyph surrounding one of the mortar holes.

 
 
The petroglyphs shown here display, from left to right, a grid pattern, then either a sunburst or wagon wheel design in the center, and last a hand is on the far right. The petroglyphs are faint and hard to see, so it may be necessary to click on the thumbnails shown here, and look closely at the more detailed images to clearly see the designs.

 
 
These pictures show on the left a reconstructed ceremonial lodge (roundhouse) near the museum, and a group of three dwelling huts made of bark are in the center. The sign on the far right from a nature garden in the patio area shows an acorn nutritional analysis.

 
 

 

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