Who Excavated all of These Mines?

Over the past few weeks, I notice that I have been running a lot of quests through various mines.  For instance, I ran Stromvauld’s Mine, The Iron Mines in Sorrowdusk Ilse, and the Scondrel’s Run.  So I started to wonder, who excavated these mines to begin with?  Now we know that Stromvauld’s Mine is an active mine and in fact that is why we are heading in there, to look for the missing mining parties.  However, the Iron Mines and Scondrel’s Run are abandoned mines that are now inhabited by ogres and minotaurs, respectively. 

Stromvauld’s mine is still actively producing rare gems.

The Iron Mines suggest that at one point iron was harvested with great quantities out of there.  I’m thinking that a clan of dwarves probably started this mine.  But what happened to them?  If dwarves didn’t set up the mine then who did.  As for Scondrel’s…