Indigenous history Long before the widespread ranching and mining activity that took place in the area, indigenous people had a presence in the Bay Area for 13,000 years. Three
Bay Miwok tribes, the
Chupcan, Ompin, and Volvon, lived in the areas surrounding the Black Diamond Mines Regional Preserve. The Chupcan occupied territory to the west of the preserve near
Concord, the Volvon occupied the territory to the south including much of
Mount Diablo, and the Ompin occupied the area to the north including
Pittsburg,
Collinsville, and the intervening waterway. Black Diamond Mines Regional Preserve is located in a boundary area between these three tribes. At the beginning of the 19th century, these three tribes were significantly impacted by the Spanish mission system. Between 1804 and 1806, the majority of Volvon Bay Miwok were split up and baptized at either
Mission Dolores or
Mission San Jose. A Spanish military raid caused the Chupcans to flee to Suisun territory in 1804, and by 1811, most Chupcans were split up and baptized at either
Mission Dolores or
Mission San Jose. His initial attempt to mine the coal was not financially successful but soon other coal deposits were discovered nearby and mining operations grew rapidly. The area became known as the Mount Diablo Coalfield, producing more than 4 million tons of coal during this time. The area includes the remains of twelve
coal mines and the sites of several long-gone coal mining towns. The Preserve contains over of mine workings. The largest and oldest town,
Nortonville, had a peak population of about 1,000.
Somersville,
Stewartville,
West Hartley and
Judsonville were located in valleys to the east. The sites of Judsonville and West Hartley are located on private property outside the eastern boundary of the Preserve. The mines were the Empire, Central, Star, Corcoran, Pittsburg, Manhattan, Eureka, Independent, Union, Black Diamond, Mt. Hope, and Cumberland. The coal produced was of a low grade (sub-bituminous or lignite), but for a time in the 19th century, was the only readily accessible and economic source in California. Therefore, it was a very valuable resource and powering the railroads, ships and heavy industry of California. The mineral was often called 'black diamond." The coal was carried to the
San Joaquin River by three railroads: the Empire, Pittsburg, and
Black Diamond, for shipment by barge to markets in
San Francisco,
Sacramento,
Stockton and other communities. Coal mining activity ended as better-quality imported coal became affordable and as petroleum emerged as an energy source. Park staff have maintained a public-access opening into a former coal mine known as Prospect Tunnel. Visitors can explore the first of this approximately 400-foot tunnel.
Rose Hill Cemetery Rose Hill Cemetery, officially designated as a Protestant cemetery, the final resting place for over 200 residents of the coalfield, is located on a hillside between the Somersville and Nortonville townsites. After the mines closed and the nearby towns were abandoned, the cemetery fell into disuse. Many of the gravestones were stolen or destroyed by vandals, or damaged by cattle using them as scratching posts. In 1960, Ansel Adams photographed two Italian Cypress trees in the cemetery, and called the image, "Poplars, Cemetery near Mount Diablo". Those buried in the cemetery include coal miners who were killed as a result of their work in the mines. However, the majority of the buried are children from the nearby towns of Nortonville and Somersville who died of diseases such as smallpox, scarlet fever, diphtheria, and typhoid. The land the cemetery occupies was originally owned by the
Black Diamond Coal Mining Company president and chief stockholder Alvinza Hayward, who left it to his daughter Emma Rose upon his death. In the 1940s she deeded the land to Contra Costa County. It was transferred to the East Bay Regional Park District in September 1973. Since that time park staff has undertaken restoration of the cemetery, including stabilizing eroded soil, repairing and reinstalling gravestones, and marking burial sites missing gravestones with brass plaques. A few whose earthly remains were laid to rest here include: • William Gething, age 36, who was killed with 10 other men in an 1876 mine explosion; 7 other men who died in the same accident are buried nearby. The citizens of Nortonville raised $300 to erect a white bronze monument to these men, located in the cemetery. The monument was stolen or destroyed sometime after the 1930s. Inside the Greathouse portal, a -long section of the entrance corridor has been made into a museum. The first section is a series of self-guided exhibits, while the larger second section (which has a separate entrance from the outside), houses a reconstruction of the Hazel-Atlas works as it would have appeared around 1940. Park staff originally repurposed the Hazel-Atlas mine as a museum in the 1970s, but storm damage in 2007 forced closure of this attraction for extensive repairs. It did not reopen for five years. == Geology ==