1942 Map of Polvadero Gap

About this map

The Southern San Joaquin Valley transitions from flat agricultural plains into the intricate folds of the Kettleman Hills and Guijarral Hills in this 1942 War Department survey. The topography is dominated by the massive ridge systems and the distinctive Polvadero Gap, where the landscape is carved by numerous seasonal drainages like Arroyo Pasajero and Zapato Creek. This era of the valley’s development is marked by a network of ranching outposts, including Zubeldia Ranch and Kreyenhagen Ranch, which stood as isolated landmarks in the arid terrain before modern irrigation and oil expansion fully transformed the region.