From the 1860s to the turn of the 20th century, the Mount Diablo Coal Field was the largest coal-producing region in California and once boasted five thriving communities. With the decline of coal mining some residents turned to ranching. Later rich deposits of sand were mined for glass and foundry use. In 1973, the East Bay Regional Park District acquired the land. Today visitors to Black Diamond Mines Regional Preserve, located 45 miles east of San Francisco, can explore miles of trails, tour the Hazel-Atlas silica sand mine, and visit historic Rose Hill Cemetery.
Drawing mainly from the vast collection of the preserve's photographs, Traci Parent and Karen Terhune have assembled this compelling pictorial history. For over 30 years, Traci Parent, Black Diamond Mines supervising naturalist, board member, and past president of the Contra Costa County Historical Society, has researched and documented the history of the coal field. She received an award from the Conference of California Historical Societies for her book on Rose Hill Cemetery. Black Diamond volunteer Karen Terhune has edited, formatted, and conducted research on various coalfield oral history transcriptions. She is a member of the California Writers' Club, Mount Diablo Branch, and the CCH S.