
The northern edge of the Mt Diablo Base Line meets the expanding industrial and residential fringes of Antioch in this mid-century survey. Heavy industry is concentrated along the Southern Pacific Railroad, evidenced by a massive Filtration Plant and extensive clusters of Oil Tanks. Southward, the landscape shifts into the cattle-and-canyon country of the Morgan Territory. Here, several vanished mining and ranching settlements are preserved as sites, including Somersville, Stewartville, and West Hartley, the latter noted for its Coal Mine Tunnels. The terrain is deeply carved by water and infrastructure, from natural landmarks like Markley Canyon to the massive Mokelume River Aqueduct and Contra Costa Canal. Notable social markers of the era include the County Jail Farm and the Morgan Territory Sch (Aband), reflecting a shift in rural education and land use during the 1950s and 1960s.
50 named features on this map. Tap any name to fly to it.
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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