1956 Map of Mendota Dam

About this map

The San Joaquin River and a complex network of man-made waterways define the landscape of this Central Valley region during the mid-20th century. At the heart of this irrigation and water management system sits the Mendota Dam, regulating flow into the Mendota Pool. The map illustrates a transitional period for the area, where the vast agricultural holdings of the New Columbia Ranch, Pomona Ranch, and Aliso Ranch coexist with emerging energy infrastructure, evidenced by scattered Gas Wells to the east. Extensive engineering is visible through the prominent Chowchilla Canal and Delta-Mendota Canal, which cut across the natural meanders of the river and Fresno Slough. The city of Mendota appears at the southern edge, serving as a hub for this intersection of water, ranching, and industrial development.