1956 Map of Obsidian Butte

About this map

Salton Sea dominates this mid-century survey, revealing the shoreline and ecological management of the Imperial Valley during a period when the water level was recorded at 235 feet below sea level. The map highlights the volcanic landmark Obsidian Butte, where resource extraction is evident through a nearby Pumice deposit and a Quarry. This area, part of the Salton Sea National Wildlife Refuge, shows an intricate network of irrigation and drainage essential to the region's agricultural reclaimed land, including Lateral 5, Vail Drain, and the Vail Cut Off. The presence of multiple Pumps and levees along the southeastern shore illustrates the engineering efforts to control the inflow from the New River and manage the rising salinity and water levels of the landlocked sea.