A photograph showcasing the vaulted arches of a salt dome taken underground in the 1940s by the United States Geological Survey (USGS). The salt dome exists at a depth of nearly 2000 feet below the surface, and despite the temperatures reaching ~90ºF, the nearly nonexistent levels of humidity create an environment perfectly suited for natural salt preservation. | Creator: United States Geological Survey | Date: ca. 1940s | Source: https://texascooppower.com/the-salty-history-of-east-texas-lies-underground/Download Original File
