Aside from the first phase of Icecrown (which you unrevokeably pass once you start the Argent Crusade quests there), there are very véry few spots where you can easily grind Borean Leather at a high rate.
What do I define a high rate as?
- High monster uptime
- Leather acquisition guaranteed
- Monsters hit for relatively low damage.
These mobs:
- are always up. Extremely high respawn rate.
- Yield 1 Borean Leather, chance on Arctic Fur (+ various high-selling greys and Iceweb Spider Silk)
- hits for a mere 280 on a Balance druid, is sensitive to root, stun, slow effects.
Go to the Crystalweb Cavern in Storm Peaks.
You need to walk to the very end of it, where Icetip Crawlers spawn.
There they roam, three at a time, and by the time you killed the third one, the first one has respawned. Guaranteed.
Besides that, they walk in a profitable pattern, very little running is required.
Use it while you can!
But try keep it on the low voice![]()