Somersville in Contra Costa County, California — The American West (Pacific Coastal)
Eureka Slope
Photographed by Joseph Alvarado, May 7, 2022
1. Eureka Slope Marker
Inscription.
Eureka Slope. . This inclined shaft, known as Eureka Slope, was the entrance to the Eureka Coal Mine. Between 1860 and 1895, more than 150,000 tons of coal were hoisted to the surface. The slope is 290 feet long and descends at a pitch of 32 degrees. It was fitted with a self-acting, inclined railroad that allowed the weight of a descending empty mine car to partially offset the weight of an ascending loaded car. The slope was extended above grade with a wooden trestle, allowing cars to dump directly into a storage bunker. Coal from the bunker was loaded into rail cars for transportation to a wharf on the San Joaquin River, a distance of about 5.5 miles. Below the ground, the mine workings extend down more than 800 feet, eventually connecting the Independent shaft, located in the parking lot one quarter mile to the north., The East Bay Regional Park District is in the process of restoring the slope to its original appearance as a working mine entry.
This inclined shaft, known as Eureka Slope, was the entrance to the Eureka Coal Mine. Between 1860 and 1895, more than 150,000 tons of coal were hoisted to the surface. The slope is 290 feet long and descends at a pitch of 32 degrees. It was fitted with a self-acting, inclined railroad that allowed the weight of a descending empty mine car to partially offset the weight of an ascending loaded car. The slope was extended above grade with a wooden trestle, allowing cars to dump directly into a storage bunker. Coal from the bunker was loaded into rail cars for transportation to a wharf on the San Joaquin River, a distance of about 5.5 miles. Below the ground, the mine workings extend down more than 800 feet, eventually connecting the Independent shaft, located in the parking lot one quarter mile to the north.
The East Bay Regional Park District is in the process of restoring the slope to its original appearance as a working mine entry.
Location. 37° 57.274′ N, 121° 51.933′ W. Marker is in Somersville,
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California, in Contra Costa County. It can be reached from Nortonville Road. The marker is located on the hill above the mine entrance to the Greathouse Visitor Center. This is off Nortonville Road, about .3 miles south of the southern parking lot of the Black Diamond Mines Regional Preserve. Touch for map. Marker is in this post office area: Pittsburg CA 94565, United States of America. Touch for directions.
Regionally, this marker is in California’s San Francisco Bay Area and on the Coast Ranges. It is also on the American Pacific Coast. Globally, it is in North America, on the Ring of Fire, in the Pacific Rim, in the Western Hemisphere, in the Western World, and in the Anglosphere. Historically, it finds itself in what was once New Spain and also Mexicos Alta California.
Credits. This page was last revised on March 15, 2023. It was originally submitted on May 20, 2022, by Joseph Alvarado of Livermore, California. This page has been viewed 564 times since then and 28 times this year. Photos:1, 2, 3, 4. submitted on May 20, 2022, by Joseph Alvarado of Livermore, California. • J. Makali Bruton was the editor who published this page.
