Qualla: Black Diamond Mines Regional Preserve

Black Diamond Mines Regional Preserve: Introduction

Fri, 23 Jan 2026 00:00:00 GMT

Photo credit Mx. Granger, CC0. Most of the graves at Rose Hill Cemetery belong to children. Smallpox, scarlet fever, diphtheria, typhoid: the diseases that stalked 19th-century mining towns took the young first. The cemetery sits on a hillside between Nortonville and Somersville, two of five towns that once thrived here on California's only significant coal deposits. Ansel Adams photographed the Italian Cypress trees in 1960, calling his image "Poplars, Cemetery near Mount Diablo." By then, the towns had been abandoned for decades, their gravestones vandalized or used as scratching posts by cattle. The children's names, where they survive, mark a frontier childhood that few completed.

Image: Mx. Granger | CC0

Black Diamond Mines Regional Preserve: The Bay Miwok Boundary

Fri, 23 Jan 2026 00:00:00 GMT

Photo credit Falcorian, CC BY-SA 4.0. For 13,000 years before the coal mines, three Bay Miwok tribes shared this land. The Chupcan lived west toward Concord, the Volvon occupied Mount Diablo to the south, and the Ompin held the territory north to Pittsburg and the waterways beyond. The preserve sits at their boundary...

Image: Falcorian | CC BY-SA 4.0

Black Diamond Mines Regional Preserve: Four Million Tons of Black Diamond

Fri, 23 Jan 2026 00:00:00 GMT

Photo credit Robin Mayoff (RHM Images), CC BY-SA 3.0. The coal was low-grade, sub-bituminous lignite, but in 19th-century California it was the only readily accessible source. The Mount Diablo Coalfield produced over 4 million tons, powering the railroads, ships, and heavy industry of a state without petroleum. Twelve mines bore int...

Image: Robin Mayoff (RHM Images) | CC BY-SA 3.0

Black Diamond Mines Regional Preserve: Nortonville's Thousand Souls

Fri, 23 Jan 2026 00:00:00 GMT

Photo credit Mwmccune, CC BY-SA 4.0. The largest town, Nortonville, reached a peak population of about 1,000. Somersville, Stewartville, West Hartley, and Judsonville filled the valleys to the east. When an 1876 mine explosion killed 11 men, the citizens of Nortonville raised $300 to erect a white bronze monument at...

Image: Mwmccune | CC BY-SA 4.0

Black Diamond Mines Regional Preserve: From Ancient Seas to Shallow Marshes

Fri, 23 Jan 2026 00:00:00 GMT

Photo credit Peterquinn925, CC BY-SA 4.0. The coal formed during the Eocene epoch, when tectonic forces lifted the continental shelf and created shallow marshes at the edge of a sea that covered California's Central Valley. The Pacific Ocean reached the lower Sierra Nevada; the coastline sat hundreds of miles east of tod...

Image: Peterquinn925 | CC BY-SA 4.0

Black Diamond Mines Regional Preserve: Walking Through History

Fri, 23 Jan 2026 00:00:00 GMT

Photo credit Pi.1415926535, CC BY-SA 3.0. Today the East Bay Regional Park District maintains over 65 miles of trails through the preserve's grasslands, oak woodlands, and chaparral. The Prospect Tunnel opens its first 400 feet to visitors, a public window into the mine workings that honeycomb these hills. The Greathouse...

Image: Pi.1415926535 | CC BY-SA 3.0