This guide is for Retail WoW and Cataclysm Classic. I have a separate guide for Classic Era: Thorium Ore farming in Classic Winterspring I believe Winterspring is the best place for mining Thorium, there is so much Rich Thorium veins in this zone. You could actually just go off the route...
Its close to an outpost (chapel of light) for selling/buying new arrows and close to a flightpoint. There is 3 rich thorium veins in that area to be accesed in addition to mob kills. There is 1 "silver elite" mob spawnign there every 6 hours or. There is at least 3 chest spawn ...
While mostMages will focus on farming the lasher area right after falling down, you can actually solo the entire dungeon as shown by Zqi inthis detailed video, in which case havingMiningis amazing, as you get access to multiple Rich Thorium veins after the final boss, which can contain ext...