Western New York and Central New York, location of American Rock Salt, the largest operating salt mine in the United States with a capacity for producing up to 18,000 tons each day.Syracuse earned the nickname "The Salt City" for its salt mining, an activity that continues in the region to the present day.
Inside Salina Veche, Europe's largest salt mine, in Slănic, Prahova, Romania. The railing (lower middle) gives the viewer an idea of scale.
Before the advent of the internal combustion engine and earth moving equipment, mining salt was one of the most expensive and dangerous of operations, due to rapid dehydration caused by constant contact with the salt (both in the mine passages and scattered in the air as salt dust), among other problems borne of accidental excessive sodium intake. While salt is now plentiful, until the Industrial Revolution it was difficult to come by, and salt mining was often done by slave or prison labor. In ancient Rome, salt on the table was a mark of a rich patron; those who sat nearer the host were "above the salt," and those less favored were "below the salt". Roman prisoners were given the task of salt mining, and life expectancy among those sentenced was low. The Roman historian Pliny the Elder stated as an aside in his Natural History's discussion of sea water, that "[I]n Rome ... the soldier's pay was originally salt and the word 'salary' derives from it ..."