I just told CEO Keith Preston that I would export salt to him. One problem though, there don't seem to be any salt deposits. Iron, Bauxite, Gold, but no salt. Do I just mine salt anywhere?
There are salt deposits, you can only place salt mines on salt deposits. When you choose to build a salt mine (note that they are a different building from normal mines), the map will highlight the potential locations. If you do not have any, then you cannot complete the quest. See the picture for an example.