Home & Garden Columns

Travel Through Time at Black Diamond Mines

By Marta Yamamoto
Friday May 19, 2006

Atop Rose Hill Cemetery, I gaze out at the undulant hillsides and narrow canyon of Black Diamond Mines Regional Preserve. I share this peak with two hundred former 19th century residents—coal miners, their wives and children. Little remains as testament to their settlement, but their voices stir the trees. Sojourn at Black Diamond Mines to revisit past glories and relish present verdant splendor. 

With almost 6,000 acres and 65 miles of trails, this is a vast parcel of preserved land, ideal for hiking, picnicking and observing wildlife. Within grassland, foothill woodland, mixed evergreen forest and chaparral, you’ll discover Coulter pine, black sage, desert olive and dudleya providing habitat for over 100 species of birds and common mammals. Add some exotic plantings and a springtime display of wildflowers deserving the attention of Monet and the urge to visit just increases. 

Below the surface, Black Diamond Preserve offers a look into the past when coal, and then sand, were mined from its core. The discovery of coal in 1850 drew immigrants from all over the world to mine for “black diamonds.” During 40 years of existence over four millions tons of coal were removed, depleting, not the resource but the workforce. At the end of the coal era, the five boomtowns and their remaining residents packed up and left. 

The next chapter in Black Diamond history came in the 1920s when sand mining began to extract high-grade silica used in glassmaking. With better and safer mining techniques, over 1.8 millions tons were removed from underground caverns by the end of World War II, when sand ballast from Belgium usurped the local product.  

The East Bay Regional Park District came into the picture in the early 1970s when it acquired land for the preserve. One unfortunate chapter, the party and vandalism era, took place before the land was acquired, leaving its mark, though now less evident, on the mines and cemetery.  

Approaching the Preserve on Somersville Road, I felt like I was leaving the world behind me. As the canyon narrowed it drew me forward until I was surrounded only by rural buildings and pristine landscape. I was ready for outdoor exploration. Since it was too early to tour the Visitor Center, I began my exploration with a walk up Nortonville Trail, once Road, to Rose Hill Cemetery. All around me were signs of new life: the tender leaves of trees of heaven emerging through last year’s seed clusters; purple vetch and blue lupine pushing up through thickets of grass; and the sounds of bumblebees, red winged blackbirds and the wind coursing through the foliage. 

The Protestant Cemetery stands sentinel over the land’s reincarnation as a park. “Gone but not forgotten” read the stones. Life was precious in the 19th century and often too short. Mining accidents and epidemics of smallpox, diphtheria and scarlet fever took many before their time. Ages on marble and granite tombstones are carved in exact time: Mary Adams lived 49 months and 7 days, Daniel Richards 69 years, 1 month and 22 days. Four children in the Joseph family died before reaching nine years of age; by eight years most were already toiling in the mines. The cemetery remains as testament to the hard lives and the contributions of those who came for a new life. 

Even when outside temperatures rise to uncomfortable levels, it’s always a crisp 56-degrees in the epic-size Greathouse Visitor Center, open to both human and canine visitor, whether on foot or on bike. Traverse a long narrow tunnel to experience how 1920s sand miners reached their underground chamber. Small lights strung at head level emit just enough light to examine the timbered walls and ceiling, shale sides and dripping water.  

At tunnel’s end, a giant cavern opens up, vast in size and marked with evidence of its past, white areas of the desired silica, orange streaks formed of rust in the less desirable sandstone and black lines of the soot remaining from days when party bonfires burned illegally.  

The center is nicely arranged with just enough exhibits, photographs, video and brochures for information, but without distracting from the cavern itself. Handsome wood cases hold vintage Lane’s Honey and Star Wine Vinegar, a sampling of the glassware produced from the mined high-grade silica. Further on, artifacts from the towns of Nortonville and Somersville—marbles, scissors, heavy iron, teapot and lock and key—are familiar in their commonality. Displays of coal samples, common rocks and Preserve wildflowers lend a science-hand. Souvenirs for budding miners include Hazel-Atlas hardhats, hardhat flashlights and park T-shirts and caps. 

It’s a short but very scenic walk from the Visitor Center to the Hazel-Atlas Mine portal and the hillside above is a springtime display. Thick shrubs and grasses are polka-dotted with glittering colors: three-toned bush lupine in blue, violet and cream, yellow coreopsis with feathery leaves, red Indian paintbrush and white hemispherical yarrow.  

You don’t need to purchase a hardhat and flashlight for the Hazel-Atlas Mine Tour; they’re included with the price of a ticket. You’ll be glad to have them, along with a sweatshirt, for the one-hour walk 400-feet into a restored silica mine. On my tour, park guide Lauren, enthusiastically instructed and entertained us with history, geology and mining techniques.  

After locking the gate and brassing us in, the park guide showed us a narrated slide show describing precarious coal mining in 18-inch coal rooms. With an image of today’s park on screen, Lauren pointed out reminders of Somersville, like level areas and piles of rocks. The walking tour focused on sand mining techniques, in which I learned about adits, stopes, scaling rods, room-and-pillar mining, slusher buckets and fossils of ancient ghost shrimp in the sandstone walls.  

Prolong your visit with a temperature-warming hike for further mine tunnel exploration or scene stealing views. Follow the Stewartville Trail past grassland and foothills to Prospect Tunnel, excavated in 1860. Use your flashlight to explore the two hundred feet of tunnel open to the public. Another option is Railroad Bed Trail, parallel to and above Somersville Road providing you with an overview of park terrain. Most trails connect up with others for loops and extensions; I used my trail map for reference. 

Black locust trees planted by miners in the 1800s at the Lower Picnic Area shaded my final stop. Springtime added the perfume of white floral clusters decorating lacy leaves and age-old weathered trunks. Here I reflected on miners, coal, silica, wildflowers, rolling landscape and the importance of open space in our lives. Explore Black Diamond Mines Preserve, and honor this turn-of-the-century mining landmark and present day refuge.  



GETTING THERE: Take Hwy 4 to the Somersville Road exit in Antioch. Drive south (into the hills) on Somersville Road to the Preserve entrance. 

Black Diamond Mines Regional Preserve: 5175 Somersville Road, Antioch, (925) 757-2620, www.ebparks.org. Park hours 8 a.m.-dusk. Fees: $5/car, $2/dog (Seasonal weekends) 

Greathouse Visitor Center: 10 a.m.-4:30 p.m., weekends March-Nov. free. 

Hazel Atlas Mine Guided Tour: weekends at noon and 3 p.m., 15 maximum, $3/person, for advance reservations call 636-1684. 


Getting there: Take Highway 4 to the Somersville Road exit in Antioch. Drive south (into the hills) on Somersville Road to the Preserve entrance. 


Black Diamond Mines Regional Preserve: 5175 Somersville Road, Antioch, (925) 757-2620, www.ebparks.org. Park hours 8 a.m.-dusk. Fees: $5/car, $2/dog (Seasonal weekends). 


Greathouse Visitor Center: 10 a.m.-4:30 p.m., weekends March-November. Free. 


Hazel Atlas Mine Guided Tour: weekends at noon and 3 p.m., 15 maximum, $3/person. For reservations call 636-1684.