Black Diamond Mines Regional Preserve

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The Black Diamond Mines Regional Preserve is a 6,000-acre (2,400 ha) park situated north of Mount Diablo in Contra Costa County, California under East Bay Regional Park District (EBRPD) control. In 1973 the district took over the house. The preserve features ruins from three mining cities, former coal, and sand mines, and provides guided tours of an earlier sand mine. The 60 miles (97 km) of trails in the Preserve traverse rolling foothill terrain lined with grassland, California oak woodland, California mixed evergreen woodland and chaparral.

 

History
 

Indians

Native Americans lived for thousands of years in the greater Bay Area. Black Diamond was located between three tribes in the backcountry: Chupcan (Concord), Volvon (Clayton), and Ompin (Pittsburg). The Bay Miwok language was spoken by every three nations. The Bay Miwok way of life changed dramatically after 1772, with the arrival of Spanish, Mexican, and American settlers.

 

Ranching
 

Until coal was discovered, cattle ranching was the main sector in this region. Several miners also found a new life in ranching since the mines closed. Abandoned mining town buildings have become barns, railroad ties have been used as fence posts, and boilers have been turned into water pits. Initial descendants of mining families still graze cattle in the Preserve.

 

Coal Mining
 

Five coal mining towns thrived in the Black Diamond area from the 1860s through the turn of the last century: Nortonville, Somersville, Stewartville, West Hartley, and Judsonville. As the site of the largest coal mining activity in California, nearly four million tons of coal ("black diamonds") have been extracted from the earth. The inhabitants of the mining towns came from all over the world, and hard work and long hours defined their life. Occasional gatherings as well as a number of associations and social events helped to relieve the everyday drudgery.

 

Coal mining had a huge effect on the economy in California. At the time operations ceased due to the increasing cost of production and the utilization of new energy sources, most of California 's economy had been transformed from an agricultural to an urban base.

 

Sand Mining
 

Underground mining for sand started in the 1920s near the abandoned townsites of Nortonville and Somersville. The Somersville mine supplied the Hazel-Atlas Glass Company in Oakland with sand used in glassmaking, while the Nortonville mine supplied foundry (casting) sand for the Columbia Steel Works. Belgian glass competition and the closure of a steel foundry ended sand mining by 1949. More than 1.8 million tons of sand were extracted altogether.