Rockhounding Napa County, California: 8 Places To Hunt Rocks, Crystals, and Fossils  

Napa County is famously known for its prestigious wineries and some of the finest wines in the world.

What some don’t know is that Napa County is also home to some of the best rock hunting spots. Known for its interesting geological location, a vast array of rocks, crystals, and fossils can be found here.

Rockhounding Napa County (Let’s Go)


The information provided in this article by is for informational purposes and is subject to change. Laws are updated. Accessibility guidelines and restrictions change. Be sure to confirm the land status and collection rules before you travel to an unfamiliar location or collect any material.

1. Glass Beach

Address: Landfill Loop Trail, American Canyon, CA 94503, United States

Rocks Found Here: Beach glass

Glass Beach is a local hidden gem located just south of Napa.

This beach is located on the Napa River and features a stunning display of beach glass accumulated over the years.

The American Canyon section of the Napa River Bay Trail is located in a former landfill.

There is an assortment of trails you can follow here.

To get to Glass Beach, you will begin on the paved pathway which soon turns into a large dirt trail.

Once you have reached the river, you will turn left onto one of the dirt trails.

Following these dirt trails will lead you to Glass Beach approximately a mile away.

Note: Be aware of wildlife while walking on the trails.

2. Wrights Beach

Address: Shoreline Highway, Bodega Bay, CA 94923, United States

Rocks Found Here: Agate, Jasper, Jade

Wrights Beach is the largest Sandy beach, located between The Russian River and Bodega Bay.

This beach is part of Sonoma Coast State Park and features a campground, day-use areas, and hiking trails.

The majority of the sand here is made up of polished jasper and chert stones.

Agates and Jade can also be found here among other rocks.

Note: Avoid coming here on holidays as it is extremely busy then.

3. Napa Glass Mountain

Address: Napa County, CA 94574, United States

Rocks Found Here: Obsidian

Napa Glass Mountain is located just north of St. Helena on the Silverado Trail.

This section of the mountain is made up almost entirely of obsidian.

Natives used to make their tools out of a variety of rocks and minerals but found obsidian to be the best material.

Obsidian is very uncommon and only found within volcanic regions where lava has a high silica content and low water content.

The volcanic regions in Napa County make obsidian one of the more common minerals to find.

Note: Be sure to bring a map with you so you don’t get lost on the trails.

4. Petrified Forest

Address: 4100 Petrified Forest Rd, Calistoga, CA 94515, United States

Rocks Found Here: Fossils, Petrified Wood

The Petrified Forest is located just 45 minutes from Napa.

The trees here are so old they have slowly turned to rock.

When Mt St. Helena erupted, the ash-covered the knocked-down trees, turning them into rocks over time.

The trails follow a half-mile loop throughout the forest showcasing some of its most spectacular creations.

You can also choose to take a side trail named the “Meadow Trail” which veers off from the main loop and ends in a meadow.

From here you will have an incredible view of Mt St. Helena.

While this forest is protected and you are expected not to take anything, there is a gift shop available to pick up a piece of petrified wood and some fossils.

Note: Admission is $12 per person or $6 per kid.

5. Eureka Peak

Address: Eureka Peak, San Francisco, CA 94114, United States

Rocks Found Here: Smokey Quartz

Eureka Peak and the surrounding trails are an excellent spot to do some hiking and rock searching.

At Eureka Peak, you can find smokey quartz hidden within the valley if you are looking carefully.

The Eureka Valley Tuff erupted and created two ash flows going down the mountain.

Buried beneath these layers of old ash are smoky quartz and possibly some other hidden gems.

Note: Peaks may be cold and windy. Suggest bringing a jacket.

6. Six Sigma Ranch

Address: 13372 Spruce Grove Rd, Lower Lake, CA 95457, United States

Rocks Found Here: Diamonds

Six Sigma Ranch is located just over an hour away from Napa.

This ranch features a winery, trails, and a plethora of rocks.

There is a 2-mile hike to the Diamond Mine Vineyard where you will be able to find small Lake County diamonds with minimal effort.

The tour combines scenery, countryside, and an exclusive rock-hounding experience.

To hunt for diamonds here, you will need to book the Pinzgauer Vineyard Tour.

This tour includes a ride on an ATV to the high elevations of 1700ft.

At this height, you are able to search for diamonds of all shapes, sizes, and even colors.

Note: You will need to book a tour ahead of time to ensure availability.

7. Lake Berryessa

Address: 5520 Knoxville Rd, Napa, CA 94558, United States

Rocks Found Here: Jasper, Agate, Satin Spar, Cinnabar, Myrickite

Lake Berryessa is located just a short 20-minute drive from Napa.

This lake is the largest lake within Napa County.

This park features camping, swimming, boating, fishing, wildlife, and, of course, rock hunting.

Along the shores of Lake Berryessa, you can find a variety of rocks and minerals.

Agates are the most common rock found in this area, but you can also find jasper, satin spar, cinnabar, myrickite, and others.

This is a great park to take the whole family and spend the day here exploring and soaking up the sunshine.

Note: Admission is free to this location.

8. Oat Hill Mine Trail

Address: 2082 Oat Hill Mine TrailCalistoga, CA 94515, United States

Rocks Found Here: Cinnabar, Mercury

The Oat Hill Mine Trail is located just 45 minutes from Napa.

These trails follow 8.3 miles through Calistoga and Pope Valley.

While mining in the area ceased in the 1960s, there are still remnants of the mines located here.

Mining was done for Cinnabar and Mercury, which were found in large deposits.

Note: Parking here is very limited, you should park on the side of the road where it is safe to do so.

Napa Valley is your number one go-to for some amazing rock-hounding and special finds. Always remember to stay safe, be respectful, and have fun.

California Rockhounding Resources

If you like to have a physical book in hand (like when there’s no cell service), here’s a few popular options:

Rockhounding California: A Guide To The State’s Best Rockhounding Sites

Gem Trails of Southern California

Gem Trails of Northern California

Smithsonian Rocks and Minerals Identification Guide

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Rockhounding Napa County