Shashta started out as a small town that didn't have much going for it. In a location fairly far off the beaten path, its only initial purpose was to host a mining community digging for semi-valuable metals. That venture never fully panned out, leaving the town's residents numbering at less than a hundred.
Then, a vein of mana crystals was discovered. To say it was an amazing find is an understatement; Shashta counts the first time outside of Nahr that such a large supply has been discovered. As soon as word leaked out, people swarmed to the town in hopes of getting rich through the discovery, many trying to find their own vein to profit off of. It's barely been over a year, and the population of Shashta has shot up to a few thousand and is still growing.