
Somersville and Nortonville sit at the northern edge of the hills, marking the historical industrial activity of the Mount Diablo coalfields. This 1953 survey, updated in 1980, shows a landscape transitioning from resource extraction to managed regional spaces like Contra Loma Regional Park. Evidence of the area's subterranean history is visible through Coal Mine Tunnels near West Hartley, while the valley floors are defined by significant water infrastructure including the Contra Costa Canal and the Mokelumne Aqueduct. Further south, the rural character of Morgan Territory is preserved, anchored by the Morgan Territory Sch. The northern edge displays the urban expansion of Antioch, including the Antioch HS and the Antioch Municipal Reservoir, contrasting with the rugged canyons and valleys like Horse Valley and Briones Valley that dominate the central terrain.
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9 editions found
58 maps found

1896 Mt. Diablo
Contra Costa County, CA

1898 Mt. Diablo
Contra Costa County, CA

1911 Byron Hot Springs
Contra Costa County, CA

1913 Woodward Island
Contra Costa County, CA

1916 Byron Hot Springs
Contra Costa County, CA

1916 Lone Tree Valley
Contra Costa County, CA

1943 Mt. Diablo
Contra Costa County, CA

1947 Briones Valley
Contra Costa County, CA

1947 Las Trampas Ridge
Contra Costa County, CA

1949 Briones Valley
Contra Costa County, CA

1949 Las Trampas Ridge
Contra Costa County, CA

1949 Mare Island
Contra Costa County, CA

1951 Mare Island
Contra Costa County, CA

1951 Port Chicago
Contra Costa County, CA

1952 Woodward Island
Contra Costa County, CA

1953 Antioch South
Contra Costa County, CA

1953 Byron Hot Springs
Contra Costa County, CA

1953 Tassajara
Contra Costa County, CA

1959 Briones Valley
Contra Costa County, CA

1959 Las Trampas Ridge
Contra Costa County, CA

1959 Mare Island
Contra Costa County, CA

1968 Port Chicago
Contra Costa County, CA

1978 Woodward Island
Contra Costa County, CA

1991 Tassajara
Contra Costa County, CA

1993 Briones Valley
Contra Costa County, CA

1993 Las Trampas Ridge
Contra Costa County, CA

1995 Briones Valley
Contra Costa County, CA

1995 Las Trampas Ridge
Contra Costa County, CA

1996 Tassajara
Contra Costa County, CA
2012 Antioch South
Contra Costa County, CA
2012 Briones Valley
Contra Costa County, CA
2012 Byron Hot Springs
Contra Costa County, CA
2012 Las Trampas Ridge
Contra Costa County, CA
2012 Mare Island
Contra Costa County, CA
2012 Tassajara
Contra Costa County, CA
2012 Woodward Island
Contra Costa County, CA
2015 Antioch South
Contra Costa County, CA
2015 Briones Valley
Contra Costa County, CA
2015 Byron Hot Springs
Contra Costa County, CA
2015 Las Trampas Ridge
Contra Costa County, CA
2015 Mare Island
Contra Costa County, CA
2015 Tassajara
Contra Costa County, CA
2015 Woodward Island
Contra Costa County, CA
2018 Antioch South
Contra Costa County, CA
2018 Briones Valley
Contra Costa County, CA
2018 Byron Hot Springs
Contra Costa County, CA
2018 Las Trampas Ridge
Contra Costa County, CA
2018 Mare Island
Contra Costa County, CA
2018 Tassajara
Contra Costa County, CA
2018 Woodward Island
Contra Costa County, CA
2021 Antioch South
Contra Costa County, CA

2021 Briones Valley
Contra Costa County, CA

2021 Byron Hot Springs
Contra Costa County, CA

2021 Las Trampas Ridge
Contra Costa County, CA

2021 Mare Island
Contra Costa County, CA

2021 Tassajara
Contra Costa County, CA

2021 Woodward Island
Contra Costa County, CA

2023 Antioch South
Contra Costa County, CA